Contact Dermatitis

Josh struggled for more than a decade with what his doctors had told him was irritable bowel syndrome (IBS). But curiously, the 39-year-old’s flare-ups were caused by some foods that aren’t typical IBS triggers. Peanuts and shellfish caused “stabbing” abdominal pains, and he would feel lightheaded after simply inhaling the scent of them. He also had severe constipation that lasted up to a week and rectal mucous discharges.

So, Josh (not his real name) sought the care of New York gastroenterologist Yevgenia Pashinsky, MD. She conducted a comprehensive nutritional assessment and sent him for allergy testing. The results: Josh had a little-known condition called systemic nickel allergy syndrome (SNAS), which can mimic some of the symptoms of IBS.

Dr. Pashinsky, of the department of medicine at Icahn School of Medicine at Mount Sinai, New York, and a partner with New York Gastroenterology Associates, presented Josh’s case as part of a seminar on SNAS and IBS “mimickers” at the Food and Nutrition Conference and Expo in Orlando last October, sponsored by the Academy of Nutrition and Dietetics.

She and two registered dietitians in her practice, Suzie Finkel, MS, RD, CDN, and Tamara Duker Freuman, MS, RD, CDN, told seminar attendees that SNAS is rarely diagnosed and can be mistaken for IBS. They noted that it probably strikes more people than doctors suspect.

“Systemic nickel allergy is present in at least 10% of the U.S. population (and much higher in some subgroups),” Dr. Pashinsky told this news organization. “But its connection to GI symptoms and functional GI disorders is still being learned about.

“I think of nickel allergy and other allergic disorders when, in addition to GI symptoms, the patient reports skin and mucous membrane involvement along with their abdominal reactions,” she said.

For patients like Josh with SNAS, the diagnosis and treatment of this condition are surprisingly simple and effective.

“Josh had these really [unusual] symptoms and nontraditional IBS food triggers,” Ms. Finkel said in an interview. “So, that’s a situation where, as dietitians we say, ‘Hmm, that’s weird; if you have IBS, then peanuts and shrimp shouldn’t really cause an issue here.’ But this might be something physicians might not be attuned to because it’s not part of their training.”

Ms. Finkel said that Josh was referred to an allergist. Josh tested positive for skin sensitization to nickel, and he was started on a low-nickel diet, which improved his symptoms.

“So, that was this happy ending,” she added.

The upshot?

“Doctors who treat IBS patients [who are not responding to treatment] need to consider the possibility that they have SNAS and send them for allergy testing,” Ms. Finkel said. “If they come back positive, simple dietary changes can address it.”
 

An underrecognized condition

There has been very little research regarding SNAS in patients with IBS, and there are no standard guidelines for diagnosing and treating it.

What’s more, many gastroenterologists aren’t familiar with it. More than a dozen gastroenterologists who were contacted for comment declined to be interviewed because they didn’t know about SNAS – or enough about it to provide useful information for the story.

Ms. Finkel said she’s not surprised that many gastroenterologists don’t know much about how SNAS can mimic IBS, which is why she and her colleagues presented the seminar last October in Orlando. “It’s really an allergy and not a GI disease. It manifests with GI symptoms, but the root is not in the digestive tract; the root is in a true allergy – a clinical allergy – to nickel.”

Complicating the issue is that people who have IBS and those with SNAS typically share some common symptoms.

Like IBS, SNAS can cause GI symptoms – such as cramping, abdominal pain, heartburn, constipation, gaseous distension, and mucus in the stool. It can be triggered by certain fresh, cooked, and canned foods.

But the food triggers that cause SNAS are not usually those that cause IBS symptoms. Rather, SNAS flare-ups are nearly always triggered by foods with high levels of nickel. Examples include apricots, artichokes, asparagus, beans, cauliflower, chickpeas, cocoa/chocolate, figs, lentils, licorice, oats, onions, peas, peanuts, potatoes, spinach, tomatoes, and tea.

According to the American Academy of Allergy, Asthma & Immunology, a distinguishing feature of SNAS is that it can cause allergic contact dermatitis when a person touches something made with nickel. Coins, jewelry, eyeglasses, home fixtures, keys, zippers, dental devices, and even stainless-steel cookware can contain allergy-triggering nickel.

What Ms. Finkel sees the most are skin reactions from touching a surface containing nickel or from ingesting it, she said.

The other immediate symptom is abdominal pain or changes in bowel movements, such as diarrhea, she added.

Christopher Randolph, MD, an allergist based in Connecticut, told this news organization that it’s important for doctors to realize that patients who have a skin reaction to nickel may also have inflammatory GI symptoms.

“We definitely need more controlled studies,” said Dr. Randolph, of the department of allergy and immunology at Yale University, New Haven, Conn. “But the takeaway here is for patients and certainly providers to be mindful that you can have systemic reactions to nickel, even though you implicate only the contact dermatitis.”
 

Diagnosis and treatment recommendations

Skin patch allergy testing – in which a person’s skin is exposed to nickel – can quickly determine whether a patient with IBS is actually experiencing inflammatory reactions to dietary nickel and would benefit from a low-nickel or no-nickel diet, research shows.

For these patients, Dr. Pashinsky recommends the following:

• Avoiding high-nickel foods.
• Limiting canned foods.
• Using nonstainless cookware, especially for acidic foods.
• Boiling foods for potential nickel reduction, especially grains and vegetables.
• Running the tap before using water to drink or cook with first thing in the morning.

Dr. Pashisky and her team also recommend the following guidelines for doctors:

• Ask patients if symptoms occur immediately after eating certain high-nickel foods or worsen with a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet.
• Determine whether a patient is not responding to typical medical and dietary interventions used to treat IBS.
• Conduct a food/symptom history to identify potential nickel allergy triggers.
• Try a low-nickel dietary intervention to see whether a patient’s symptoms improve in a week or two.
• Refer the patient for additional diagnostic skin-patch testing or treatment.

A multidisciplinary approach

Ms. Finkel said it’s important for doctors, particularly gastroenterologists who treat patients for suspected GI disorders to consider nickel allergy as a cause.

“SNAS is this overlooked condition ... and the research is really in its nascency here,” Ms. Finkel said.

“I would say only give [a low- or no-nickel diet] consideration if the high-nickel foods are a possible trigger,” she said. “It is very specific, looking at their diet history, to have a clear hypothesis based on what their triggers are. It’s not something to try out lightly because it’s a very restrictive diet, so I would never put a patient on a diet that I didn’t think was necessary.”

Ms. Finkel added that treatment of SNAS requires a multidisciplinary approach with a gastroenterologist, an allergist, and a dietitian.

Doctors and dietitians have distinct roles in identifying and treating these patients, Ms. Finkel said.

“If there is a suspicion of IBS symptoms and the patient is not responding to first-line treatments, then it is worth having the input of a dietitian and an allergist,” she said.

A version of this article first appeared on Medscape.com.

Josh struggled for more than a decade with what his doctors had told him was irritable bowel syndrome (IBS). But curiously, the 39-year-old’s flare-ups were caused by some foods that aren’t typical IBS triggers. Peanuts and shellfish caused “stabbing” abdominal pains, and he would feel lightheaded after simply inhaling the scent of them. He also had severe constipation that lasted up to a week and rectal mucous discharges.

So, Josh (not his real name) sought the care of New York gastroenterologist Yevgenia Pashinsky, MD. She conducted a comprehensive nutritional assessment and sent him for allergy testing. The results: Josh had a little-known condition called systemic nickel allergy syndrome (SNAS), which can mimic some of the symptoms of IBS.

Dr. Pashinsky, of the department of medicine at Icahn School of Medicine at Mount Sinai, New York, and a partner with New York Gastroenterology Associates, presented Josh’s case as part of a seminar on SNAS and IBS “mimickers” at the Food and Nutrition Conference and Expo in Orlando last October, sponsored by the Academy of Nutrition and Dietetics.

She and two registered dietitians in her practice, Suzie Finkel, MS, RD, CDN, and Tamara Duker Freuman, MS, RD, CDN, told seminar attendees that SNAS is rarely diagnosed and can be mistaken for IBS. They noted that it probably strikes more people than doctors suspect.

“Systemic nickel allergy is present in at least 10% of the U.S. population (and much higher in some subgroups),” Dr. Pashinsky told this news organization. “But its connection to GI symptoms and functional GI disorders is still being learned about.

“I think of nickel allergy and other allergic disorders when, in addition to GI symptoms, the patient reports skin and mucous membrane involvement along with their abdominal reactions,” she said.

For patients like Josh with SNAS, the diagnosis and treatment of this condition are surprisingly simple and effective.

“Josh had these really [unusual] symptoms and nontraditional IBS food triggers,” Ms. Finkel said in an interview. “So, that’s a situation where, as dietitians we say, ‘Hmm, that’s weird; if you have IBS, then peanuts and shrimp shouldn’t really cause an issue here.’ But this might be something physicians might not be attuned to because it’s not part of their training.”

Ms. Finkel said that Josh was referred to an allergist. Josh tested positive for skin sensitization to nickel, and he was started on a low-nickel diet, which improved his symptoms.

“So, that was this happy ending,” she added.

The upshot?

“Doctors who treat IBS patients [who are not responding to treatment] need to consider the possibility that they have SNAS and send them for allergy testing,” Ms. Finkel said. “If they come back positive, simple dietary changes can address it.”
 

An underrecognized condition

There has been very little research regarding SNAS in patients with IBS, and there are no standard guidelines for diagnosing and treating it.

What’s more, many gastroenterologists aren’t familiar with it. More than a dozen gastroenterologists who were contacted for comment declined to be interviewed because they didn’t know about SNAS – or enough about it to provide useful information for the story.

Ms. Finkel said she’s not surprised that many gastroenterologists don’t know much about how SNAS can mimic IBS, which is why she and her colleagues presented the seminar last October in Orlando. “It’s really an allergy and not a GI disease. It manifests with GI symptoms, but the root is not in the digestive tract; the root is in a true allergy – a clinical allergy – to nickel.”

Complicating the issue is that people who have IBS and those with SNAS typically share some common symptoms.

Like IBS, SNAS can cause GI symptoms – such as cramping, abdominal pain, heartburn, constipation, gaseous distension, and mucus in the stool. It can be triggered by certain fresh, cooked, and canned foods.

But the food triggers that cause SNAS are not usually those that cause IBS symptoms. Rather, SNAS flare-ups are nearly always triggered by foods with high levels of nickel. Examples include apricots, artichokes, asparagus, beans, cauliflower, chickpeas, cocoa/chocolate, figs, lentils, licorice, oats, onions, peas, peanuts, potatoes, spinach, tomatoes, and tea.

According to the American Academy of Allergy, Asthma & Immunology, a distinguishing feature of SNAS is that it can cause allergic contact dermatitis when a person touches something made with nickel. Coins, jewelry, eyeglasses, home fixtures, keys, zippers, dental devices, and even stainless-steel cookware can contain allergy-triggering nickel.

What Ms. Finkel sees the most are skin reactions from touching a surface containing nickel or from ingesting it, she said.

The other immediate symptom is abdominal pain or changes in bowel movements, such as diarrhea, she added.

Christopher Randolph, MD, an allergist based in Connecticut, told this news organization that it’s important for doctors to realize that patients who have a skin reaction to nickel may also have inflammatory GI symptoms.

“We definitely need more controlled studies,” said Dr. Randolph, of the department of allergy and immunology at Yale University, New Haven, Conn. “But the takeaway here is for patients and certainly providers to be mindful that you can have systemic reactions to nickel, even though you implicate only the contact dermatitis.”
 

Diagnosis and treatment recommendations

Skin patch allergy testing – in which a person’s skin is exposed to nickel – can quickly determine whether a patient with IBS is actually experiencing inflammatory reactions to dietary nickel and would benefit from a low-nickel or no-nickel diet, research shows.

For these patients, Dr. Pashinsky recommends the following:

• Avoiding high-nickel foods.
• Limiting canned foods.
• Using nonstainless cookware, especially for acidic foods.
• Boiling foods for potential nickel reduction, especially grains and vegetables.
• Running the tap before using water to drink or cook with first thing in the morning.

Dr. Pashisky and her team also recommend the following guidelines for doctors:

• Ask patients if symptoms occur immediately after eating certain high-nickel foods or worsen with a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet.
• Determine whether a patient is not responding to typical medical and dietary interventions used to treat IBS.
• Conduct a food/symptom history to identify potential nickel allergy triggers.
• Try a low-nickel dietary intervention to see whether a patient’s symptoms improve in a week or two.
• Refer the patient for additional diagnostic skin-patch testing or treatment.

A multidisciplinary approach

Ms. Finkel said it’s important for doctors, particularly gastroenterologists who treat patients for suspected GI disorders to consider nickel allergy as a cause.

“SNAS is this overlooked condition ... and the research is really in its nascency here,” Ms. Finkel said.

“I would say only give [a low- or no-nickel diet] consideration if the high-nickel foods are a possible trigger,” she said. “It is very specific, looking at their diet history, to have a clear hypothesis based on what their triggers are. It’s not something to try out lightly because it’s a very restrictive diet, so I would never put a patient on a diet that I didn’t think was necessary.”

Ms. Finkel added that treatment of SNAS requires a multidisciplinary approach with a gastroenterologist, an allergist, and a dietitian.

Doctors and dietitians have distinct roles in identifying and treating these patients, Ms. Finkel said.

“If there is a suspicion of IBS symptoms and the patient is not responding to first-line treatments, then it is worth having the input of a dietitian and an allergist,” she said.

A version of this article first appeared on Medscape.com.

Josh struggled for more than a decade with what his doctors had told him was irritable bowel syndrome (IBS). But curiously, the 39-year-old’s flare-ups were caused by some foods that aren’t typical IBS triggers. Peanuts and shellfish caused “stabbing” abdominal pains, and he would feel lightheaded after simply inhaling the scent of them. He also had severe constipation that lasted up to a week and rectal mucous discharges.

So, Josh (not his real name) sought the care of New York gastroenterologist Yevgenia Pashinsky, MD. She conducted a comprehensive nutritional assessment and sent him for allergy testing. The results: Josh had a little-known condition called systemic nickel allergy syndrome (SNAS), which can mimic some of the symptoms of IBS.

Dr. Pashinsky, of the department of medicine at Icahn School of Medicine at Mount Sinai, New York, and a partner with New York Gastroenterology Associates, presented Josh’s case as part of a seminar on SNAS and IBS “mimickers” at the Food and Nutrition Conference and Expo in Orlando last October, sponsored by the Academy of Nutrition and Dietetics.

She and two registered dietitians in her practice, Suzie Finkel, MS, RD, CDN, and Tamara Duker Freuman, MS, RD, CDN, told seminar attendees that SNAS is rarely diagnosed and can be mistaken for IBS. They noted that it probably strikes more people than doctors suspect.

“Systemic nickel allergy is present in at least 10% of the U.S. population (and much higher in some subgroups),” Dr. Pashinsky told this news organization. “But its connection to GI symptoms and functional GI disorders is still being learned about.

“I think of nickel allergy and other allergic disorders when, in addition to GI symptoms, the patient reports skin and mucous membrane involvement along with their abdominal reactions,” she said.

For patients like Josh with SNAS, the diagnosis and treatment of this condition are surprisingly simple and effective.

“Josh had these really [unusual] symptoms and nontraditional IBS food triggers,” Ms. Finkel said in an interview. “So, that’s a situation where, as dietitians we say, ‘Hmm, that’s weird; if you have IBS, then peanuts and shrimp shouldn’t really cause an issue here.’ But this might be something physicians might not be attuned to because it’s not part of their training.”

Ms. Finkel said that Josh was referred to an allergist. Josh tested positive for skin sensitization to nickel, and he was started on a low-nickel diet, which improved his symptoms.

“So, that was this happy ending,” she added.

The upshot?

“Doctors who treat IBS patients [who are not responding to treatment] need to consider the possibility that they have SNAS and send them for allergy testing,” Ms. Finkel said. “If they come back positive, simple dietary changes can address it.”
 

An underrecognized condition

There has been very little research regarding SNAS in patients with IBS, and there are no standard guidelines for diagnosing and treating it.

What’s more, many gastroenterologists aren’t familiar with it. More than a dozen gastroenterologists who were contacted for comment declined to be interviewed because they didn’t know about SNAS – or enough about it to provide useful information for the story.

Ms. Finkel said she’s not surprised that many gastroenterologists don’t know much about how SNAS can mimic IBS, which is why she and her colleagues presented the seminar last October in Orlando. “It’s really an allergy and not a GI disease. It manifests with GI symptoms, but the root is not in the digestive tract; the root is in a true allergy – a clinical allergy – to nickel.”

Complicating the issue is that people who have IBS and those with SNAS typically share some common symptoms.

Like IBS, SNAS can cause GI symptoms – such as cramping, abdominal pain, heartburn, constipation, gaseous distension, and mucus in the stool. It can be triggered by certain fresh, cooked, and canned foods.

But the food triggers that cause SNAS are not usually those that cause IBS symptoms. Rather, SNAS flare-ups are nearly always triggered by foods with high levels of nickel. Examples include apricots, artichokes, asparagus, beans, cauliflower, chickpeas, cocoa/chocolate, figs, lentils, licorice, oats, onions, peas, peanuts, potatoes, spinach, tomatoes, and tea.

According to the American Academy of Allergy, Asthma & Immunology, a distinguishing feature of SNAS is that it can cause allergic contact dermatitis when a person touches something made with nickel. Coins, jewelry, eyeglasses, home fixtures, keys, zippers, dental devices, and even stainless-steel cookware can contain allergy-triggering nickel.

What Ms. Finkel sees the most are skin reactions from touching a surface containing nickel or from ingesting it, she said.

The other immediate symptom is abdominal pain or changes in bowel movements, such as diarrhea, she added.

Christopher Randolph, MD, an allergist based in Connecticut, told this news organization that it’s important for doctors to realize that patients who have a skin reaction to nickel may also have inflammatory GI symptoms.

“We definitely need more controlled studies,” said Dr. Randolph, of the department of allergy and immunology at Yale University, New Haven, Conn. “But the takeaway here is for patients and certainly providers to be mindful that you can have systemic reactions to nickel, even though you implicate only the contact dermatitis.”
 

Diagnosis and treatment recommendations

Skin patch allergy testing – in which a person’s skin is exposed to nickel – can quickly determine whether a patient with IBS is actually experiencing inflammatory reactions to dietary nickel and would benefit from a low-nickel or no-nickel diet, research shows.

For these patients, Dr. Pashinsky recommends the following:

• Avoiding high-nickel foods.
• Limiting canned foods.
• Using nonstainless cookware, especially for acidic foods.
• Boiling foods for potential nickel reduction, especially grains and vegetables.
• Running the tap before using water to drink or cook with first thing in the morning.

Dr. Pashisky and her team also recommend the following guidelines for doctors:

• Ask patients if symptoms occur immediately after eating certain high-nickel foods or worsen with a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet.
• Determine whether a patient is not responding to typical medical and dietary interventions used to treat IBS.
• Conduct a food/symptom history to identify potential nickel allergy triggers.
• Try a low-nickel dietary intervention to see whether a patient’s symptoms improve in a week or two.
• Refer the patient for additional diagnostic skin-patch testing or treatment.

A multidisciplinary approach

Ms. Finkel said it’s important for doctors, particularly gastroenterologists who treat patients for suspected GI disorders to consider nickel allergy as a cause.

“SNAS is this overlooked condition ... and the research is really in its nascency here,” Ms. Finkel said.

“I would say only give [a low- or no-nickel diet] consideration if the high-nickel foods are a possible trigger,” she said. “It is very specific, looking at their diet history, to have a clear hypothesis based on what their triggers are. It’s not something to try out lightly because it’s a very restrictive diet, so I would never put a patient on a diet that I didn’t think was necessary.”

Ms. Finkel added that treatment of SNAS requires a multidisciplinary approach with a gastroenterologist, an allergist, and a dietitian.

Doctors and dietitians have distinct roles in identifying and treating these patients, Ms. Finkel said.

“If there is a suspicion of IBS symptoms and the patient is not responding to first-line treatments, then it is worth having the input of a dietitian and an allergist,” she said.

A version of this article first appeared on Medscape.com.

Radiation dermatitis is one of the most common side effects of radiotherapy for women with breast cancer. Results from a phase 3 trial add to previous evidence from smaller trials that show that a silicone-based film can protect skin from this side effect. 

But it is not being used much in clinical practice. Instead, radiation dermatitis is usually treated after the fact, most often with aqueous creams.

The product is Mepitel film, from Swedish medical device company Mölnlycke Health Care.

It should be used for women who are at high risk for developing radiation dermatitis, said Edward Chow, MBBS, PhD, of the department of radiation oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, who was the senior author of the phase 3 study published recently in the Journal of Clinical Oncology.

“Other doctors think that because radiation dermatitis isn’t life-threatening it isn’t as important, but the condition does affect the quality of life for patients,” Dr. Chow said. “If we can lessen the pain and discomfort, why wouldn’t we as physicians?”

Dr. Chow’s open-label, multicenter trial was conducted in 376 women with large breasts (bra cup size C or larger) who were undergoing radiotherapy after lumpectomy or mastectomy. The primary endpoint was grade 2 or 3 radiation dermatitis using the Common Terminology Criteria for Adverse Events. (Grade 2 is described as moderate, whereas grade 3 is severe.) 

The film significantly reduced the incidence of grade 2 or 3 radiation dermatitis, down to  15.5% compared with 45.6% in patients receiving standard care (odds ratio, 0.20, 95% confidence interval, 0.12-0.34, P < .0001). 

There was also a significant reduction in grade 3 radiation dermatitis (2.8% vs. 13.6%; OR, 0.19; P < .0002) and moist desquamation (8% vs. 19.2%; OR, 0.36; P = .002).

“The film was remarkably effective and helped protect patients from potentially debilitating side effects,” commented Corey Speers, MD, PhD, a radiation oncologist with University Hospitals, Cleveland, who saw the study data presented during a plenary session at the annual meeting of the American Society of Clinical Oncology.

He believes that preventing radiation dermatitis before it develops is the best way to care for patients. 

“[Radiation dermatitis] is usually associated with pain and discomfort and can lead to more serious issues like infection or delayed wound healing, and unfortunately, there aren’t effective treatments for it once it’s developed, so preventing it is our most effective strategy,” Dr. Speers said. 

One reason for the film not being used much could be that it takes time apply the film, suggested Patries Herst, PhD, department of radiation therapy, University of Otago, Wellington, New Zealand. She was the lead author of a study published in 2014 that also analyzed the effectiveness of the film in preventing radiation dermatitis.

In their trial, a research radiation therapist applied the film to women when they were starting their radiotherapy. The film is applied to a portion of the breast or chest wall, and Dr. Herst emphasized the importance of applying the film correctly, making sure the film is not stretched during application and not overlapping other pieces of the film, while also making sure that it conforms to the breast shape. The film was replaced when it would curl too much around the sides, approximately every 1 or 2 weeks. 

“Radiation therapy itself is very short. And so you have about 10 minutes for every patient,” she explained.

“But applying the film adds 20-30 minutes and it’s really awkward to apply properly,” Dr. Herst said. “You have to tap it in and then have to maybe cut it so that it fits better. And hospitals say, ‘We don’t have the time’ and that is still the biggest issue that we’re seeing right now.”

In Dr. Chow’s study, the average time spent applying the film on lumpectomy patients was 55 minutes and was slightly shorter at 45 minutes for mastectomy patients. He acknowledged that it does take time that staff at most hospitals and clinics simply don’t have.

Dr. Chow suggested that perhaps a family member or other caregiver could apply the film, and he referenced an educational video from the manufacturer that provides in-depth instructions on the correct way to apply the film for radiotherapy patients. However, this could lead to errors and a waste of product if not the film was not applied properly. 

The cost of Mepitel film may also be a deterrent. Dr. Chow’s study noted that, during the entire course of radiotherapy, the cost for the film was about $80-$100 per patient. However, he believes the benefits outweigh the cost. 

In addition, there have been issues with supplies, and it has been difficult for people to get their hands on the actual product.

Currently, the Mayo Clinic is also conducting a study testing Mepitel Film for radiation dermatitis in breast cancer patients following mastectomy. Mayo Clinic principal investigator Kimberly Corbin, MD, could not go into great detail about the ongoing trial, but she said it has been difficult to get the product. 

“We have been using the film at Mayo for a number of years,” Dr. Corbin said, but we “have found that it is challenging to get supplies.”

“While we have generally been able to have some supply established through our store here, we know that is not typical and it is difficult for patients to access,” she said. In addition, “there are not a ton of centers with experience in application.”

A representative with Mölnlycke Health Care, Allyson Bower-Willner, could not comment on the distribution of Mepitel film in the United States or if the company plans to increase the amount of product shipped. The film is available “to a limited set of customers,” she said.

A version of this article first appeared on Medscape.com.

Radiation dermatitis is one of the most common side effects of radiotherapy for women with breast cancer. Results from a phase 3 trial add to previous evidence from smaller trials that show that a silicone-based film can protect skin from this side effect. 

But it is not being used much in clinical practice. Instead, radiation dermatitis is usually treated after the fact, most often with aqueous creams.

The product is Mepitel film, from Swedish medical device company Mölnlycke Health Care.

It should be used for women who are at high risk for developing radiation dermatitis, said Edward Chow, MBBS, PhD, of the department of radiation oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, who was the senior author of the phase 3 study published recently in the Journal of Clinical Oncology.

“Other doctors think that because radiation dermatitis isn’t life-threatening it isn’t as important, but the condition does affect the quality of life for patients,” Dr. Chow said. “If we can lessen the pain and discomfort, why wouldn’t we as physicians?”

Dr. Chow’s open-label, multicenter trial was conducted in 376 women with large breasts (bra cup size C or larger) who were undergoing radiotherapy after lumpectomy or mastectomy. The primary endpoint was grade 2 or 3 radiation dermatitis using the Common Terminology Criteria for Adverse Events. (Grade 2 is described as moderate, whereas grade 3 is severe.) 

The film significantly reduced the incidence of grade 2 or 3 radiation dermatitis, down to  15.5% compared with 45.6% in patients receiving standard care (odds ratio, 0.20, 95% confidence interval, 0.12-0.34, P < .0001). 

There was also a significant reduction in grade 3 radiation dermatitis (2.8% vs. 13.6%; OR, 0.19; P < .0002) and moist desquamation (8% vs. 19.2%; OR, 0.36; P = .002).

“The film was remarkably effective and helped protect patients from potentially debilitating side effects,” commented Corey Speers, MD, PhD, a radiation oncologist with University Hospitals, Cleveland, who saw the study data presented during a plenary session at the annual meeting of the American Society of Clinical Oncology.

He believes that preventing radiation dermatitis before it develops is the best way to care for patients. 

“[Radiation dermatitis] is usually associated with pain and discomfort and can lead to more serious issues like infection or delayed wound healing, and unfortunately, there aren’t effective treatments for it once it’s developed, so preventing it is our most effective strategy,” Dr. Speers said. 

One reason for the film not being used much could be that it takes time apply the film, suggested Patries Herst, PhD, department of radiation therapy, University of Otago, Wellington, New Zealand. She was the lead author of a study published in 2014 that also analyzed the effectiveness of the film in preventing radiation dermatitis.

In their trial, a research radiation therapist applied the film to women when they were starting their radiotherapy. The film is applied to a portion of the breast or chest wall, and Dr. Herst emphasized the importance of applying the film correctly, making sure the film is not stretched during application and not overlapping other pieces of the film, while also making sure that it conforms to the breast shape. The film was replaced when it would curl too much around the sides, approximately every 1 or 2 weeks. 

“Radiation therapy itself is very short. And so you have about 10 minutes for every patient,” she explained.

“But applying the film adds 20-30 minutes and it’s really awkward to apply properly,” Dr. Herst said. “You have to tap it in and then have to maybe cut it so that it fits better. And hospitals say, ‘We don’t have the time’ and that is still the biggest issue that we’re seeing right now.”

In Dr. Chow’s study, the average time spent applying the film on lumpectomy patients was 55 minutes and was slightly shorter at 45 minutes for mastectomy patients. He acknowledged that it does take time that staff at most hospitals and clinics simply don’t have.

Dr. Chow suggested that perhaps a family member or other caregiver could apply the film, and he referenced an educational video from the manufacturer that provides in-depth instructions on the correct way to apply the film for radiotherapy patients. However, this could lead to errors and a waste of product if not the film was not applied properly. 

The cost of Mepitel film may also be a deterrent. Dr. Chow’s study noted that, during the entire course of radiotherapy, the cost for the film was about $80-$100 per patient. However, he believes the benefits outweigh the cost. 

In addition, there have been issues with supplies, and it has been difficult for people to get their hands on the actual product.

Currently, the Mayo Clinic is also conducting a study testing Mepitel Film for radiation dermatitis in breast cancer patients following mastectomy. Mayo Clinic principal investigator Kimberly Corbin, MD, could not go into great detail about the ongoing trial, but she said it has been difficult to get the product. 

“We have been using the film at Mayo for a number of years,” Dr. Corbin said, but we “have found that it is challenging to get supplies.”

“While we have generally been able to have some supply established through our store here, we know that is not typical and it is difficult for patients to access,” she said. In addition, “there are not a ton of centers with experience in application.”

A representative with Mölnlycke Health Care, Allyson Bower-Willner, could not comment on the distribution of Mepitel film in the United States or if the company plans to increase the amount of product shipped. The film is available “to a limited set of customers,” she said.

A version of this article first appeared on Medscape.com.

Radiation dermatitis is one of the most common side effects of radiotherapy for women with breast cancer. Results from a phase 3 trial add to previous evidence from smaller trials that show that a silicone-based film can protect skin from this side effect. 

But it is not being used much in clinical practice. Instead, radiation dermatitis is usually treated after the fact, most often with aqueous creams.

The product is Mepitel film, from Swedish medical device company Mölnlycke Health Care.

It should be used for women who are at high risk for developing radiation dermatitis, said Edward Chow, MBBS, PhD, of the department of radiation oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, who was the senior author of the phase 3 study published recently in the Journal of Clinical Oncology.

“Other doctors think that because radiation dermatitis isn’t life-threatening it isn’t as important, but the condition does affect the quality of life for patients,” Dr. Chow said. “If we can lessen the pain and discomfort, why wouldn’t we as physicians?”

Dr. Chow’s open-label, multicenter trial was conducted in 376 women with large breasts (bra cup size C or larger) who were undergoing radiotherapy after lumpectomy or mastectomy. The primary endpoint was grade 2 or 3 radiation dermatitis using the Common Terminology Criteria for Adverse Events. (Grade 2 is described as moderate, whereas grade 3 is severe.) 

The film significantly reduced the incidence of grade 2 or 3 radiation dermatitis, down to  15.5% compared with 45.6% in patients receiving standard care (odds ratio, 0.20, 95% confidence interval, 0.12-0.34, P < .0001). 

There was also a significant reduction in grade 3 radiation dermatitis (2.8% vs. 13.6%; OR, 0.19; P < .0002) and moist desquamation (8% vs. 19.2%; OR, 0.36; P = .002).

“The film was remarkably effective and helped protect patients from potentially debilitating side effects,” commented Corey Speers, MD, PhD, a radiation oncologist with University Hospitals, Cleveland, who saw the study data presented during a plenary session at the annual meeting of the American Society of Clinical Oncology.

He believes that preventing radiation dermatitis before it develops is the best way to care for patients. 

“[Radiation dermatitis] is usually associated with pain and discomfort and can lead to more serious issues like infection or delayed wound healing, and unfortunately, there aren’t effective treatments for it once it’s developed, so preventing it is our most effective strategy,” Dr. Speers said. 

One reason for the film not being used much could be that it takes time apply the film, suggested Patries Herst, PhD, department of radiation therapy, University of Otago, Wellington, New Zealand. She was the lead author of a study published in 2014 that also analyzed the effectiveness of the film in preventing radiation dermatitis.

In their trial, a research radiation therapist applied the film to women when they were starting their radiotherapy. The film is applied to a portion of the breast or chest wall, and Dr. Herst emphasized the importance of applying the film correctly, making sure the film is not stretched during application and not overlapping other pieces of the film, while also making sure that it conforms to the breast shape. The film was replaced when it would curl too much around the sides, approximately every 1 or 2 weeks. 

“Radiation therapy itself is very short. And so you have about 10 minutes for every patient,” she explained.

“But applying the film adds 20-30 minutes and it’s really awkward to apply properly,” Dr. Herst said. “You have to tap it in and then have to maybe cut it so that it fits better. And hospitals say, ‘We don’t have the time’ and that is still the biggest issue that we’re seeing right now.”

In Dr. Chow’s study, the average time spent applying the film on lumpectomy patients was 55 minutes and was slightly shorter at 45 minutes for mastectomy patients. He acknowledged that it does take time that staff at most hospitals and clinics simply don’t have.

Dr. Chow suggested that perhaps a family member or other caregiver could apply the film, and he referenced an educational video from the manufacturer that provides in-depth instructions on the correct way to apply the film for radiotherapy patients. However, this could lead to errors and a waste of product if not the film was not applied properly. 

The cost of Mepitel film may also be a deterrent. Dr. Chow’s study noted that, during the entire course of radiotherapy, the cost for the film was about $80-$100 per patient. However, he believes the benefits outweigh the cost. 

In addition, there have been issues with supplies, and it has been difficult for people to get their hands on the actual product.

Currently, the Mayo Clinic is also conducting a study testing Mepitel Film for radiation dermatitis in breast cancer patients following mastectomy. Mayo Clinic principal investigator Kimberly Corbin, MD, could not go into great detail about the ongoing trial, but she said it has been difficult to get the product. 

“We have been using the film at Mayo for a number of years,” Dr. Corbin said, but we “have found that it is challenging to get supplies.”

“While we have generally been able to have some supply established through our store here, we know that is not typical and it is difficult for patients to access,” she said. In addition, “there are not a ton of centers with experience in application.”

A representative with Mölnlycke Health Care, Allyson Bower-Willner, could not comment on the distribution of Mepitel film in the United States or if the company plans to increase the amount of product shipped. The film is available “to a limited set of customers,” she said.

A version of this article first appeared on Medscape.com.

Etiology

Calcareous soils of central and southwest China are home to Primula obconica¹ (also known as German primrose and Libre Magenta).²Primula obconica was introduced to Europe in the 1880s, where it became a popular ornamental and decorative household plant (Figure).³ It also is a frequent resident of greenhouses.

Primula obconica is a member of the family Primulaceae, which comprises semi-evergreen perennials. The genus name Primula is derived from Latin meaning “first”; obconica refers to the conelike shape of the plant’s vivid, cerise-red flowers.

Allergens From P obconica

The allergens primin (2-methoxy-6-pentyl-1,4-benzoquinone) and miconidin (2-methoxy-6-pentyl-1, 4-dihydroxybenzene) have been isolated from P obconica stems, leaves, and flowers. Allergies to P obconica are much more commonly detected in Europe than in the United States because the plant is part of standard allergen screening in dermatology clinics in Europe.⁴ In a British patch test study of 234 patients with hand dermatitis, 34 displayed immediate or delayed sensitization to P obconica allergens.⁵ However, in another study, researchers who surveyed the incidence of P obconica allergic contact dermatitis (CD) in the United Kingdom found a notable decline in the number of primin-positive patch tests from 1995 to 2000, which likely was attributable to a decrease in the number of plant retailers who stocked P obconica and the availability of primin-free varieties from 50% of suppliers.³ Furthermore, a study in the United States of 567 consecutive patch tests that included primin as part of standard screening found only 1 positive reaction, suggesting that routine patch testing for P obconica in the United States would have a low yield unless the patient has a relevant history.⁴

Cutaneous Presentation

Clinical features of P obconica–induced dermatitis include fingertip dermatitis, as well as facial, hand, and forearm dermatitis.⁶ Patients typically present with lichenification and fissuring of the fingertips; fingertip vesicular dermatitis; or linear erythematous streaks, vesicles, and bullae on the forearms, hands, and face. Vesicles and bullae can be hemorrhagic in patients with pompholyxlike lesions.⁷

Some patients have been reported to present with facial angioedema; the clinical diagnosis of CD can be challenging when facial edema is more prominent than eczema.⁶ Furthermore, in a reported case of P obconica CD, the patient’s vesicular hand dermatitis became pustular and spread to the face.⁸

Allergy Testing

Patch testing is performed with synthetic primin to detect allergens of P obconica in patients who are sensitive to them, which can be useful because Primula dermatitis can have variable presentations and cases can be missed if patch testing is not performed.⁹ Diagnostic mimics—herpes simplex, pompholyx, seborrheic dermatitis, and scabies—should be considered before patch testing.⁷

Prevention and Treatment

Preventive Measures—Ideally, once CD occurs in response to P obconica, handling of and other exposure to the plant should be halted; thus, prevention becomes the mainstay of treatment. Alternatively, when exposure is a necessary occupational hazard, nitrile gloves should be worn; allergenicity can be decreased by overwatering or introducing more primin-free varieties.^3,10

Cultivating the plant outdoors during the winter in milder climates can potentially decrease sensitivity because allergen production is lowest during cold months and highest during summer.¹¹ Because P obconica is commonly grown indoors, allergenicity can persist year-round.

Pharmacotherapy—Drawing on experience treating CD caused by other plants, acute and chronic P obconica CD are primarily treated with a topical steroid or, if the face or genitals are affected, with a steroid-sparing agent, such as tacrolimus.¹² A cool compress of water, saline, or Burow solution (aluminum acetate in water) can help decrease acute inflammation, especially in the setting of vesiculation.¹³

Mild CD also can be treated with a barrier cream and lipid-rich moisturizer. Their effectiveness likely is due to increased hydration and aiding impaired skin-barrier repair.¹⁴

Some success in treating chronic CD also has been reported with psoralen plus UVA and UVB light therapy, which function as local immunosuppressants, thus decreasing inflammation.¹⁵

Final Thoughts

Contact dermatitis caused by P obconica is common in Europe but less common in the United States and therefore often is underrecognized. Avoiding contact with the plant should be strongly recommended to allergic persons. Primula obconica allergic CD can be treated with a topical steroid.

Etiology

Calcareous soils of central and southwest China are home to Primula obconica¹ (also known as German primrose and Libre Magenta).²Primula obconica was introduced to Europe in the 1880s, where it became a popular ornamental and decorative household plant (Figure).³ It also is a frequent resident of greenhouses.

Primula obconica is a member of the family Primulaceae, which comprises semi-evergreen perennials. The genus name Primula is derived from Latin meaning “first”; obconica refers to the conelike shape of the plant’s vivid, cerise-red flowers.

Allergens From P obconica

The allergens primin (2-methoxy-6-pentyl-1,4-benzoquinone) and miconidin (2-methoxy-6-pentyl-1, 4-dihydroxybenzene) have been isolated from P obconica stems, leaves, and flowers. Allergies to P obconica are much more commonly detected in Europe than in the United States because the plant is part of standard allergen screening in dermatology clinics in Europe.⁴ In a British patch test study of 234 patients with hand dermatitis, 34 displayed immediate or delayed sensitization to P obconica allergens.⁵ However, in another study, researchers who surveyed the incidence of P obconica allergic contact dermatitis (CD) in the United Kingdom found a notable decline in the number of primin-positive patch tests from 1995 to 2000, which likely was attributable to a decrease in the number of plant retailers who stocked P obconica and the availability of primin-free varieties from 50% of suppliers.³ Furthermore, a study in the United States of 567 consecutive patch tests that included primin as part of standard screening found only 1 positive reaction, suggesting that routine patch testing for P obconica in the United States would have a low yield unless the patient has a relevant history.⁴

Cutaneous Presentation

Clinical features of P obconica–induced dermatitis include fingertip dermatitis, as well as facial, hand, and forearm dermatitis.⁶ Patients typically present with lichenification and fissuring of the fingertips; fingertip vesicular dermatitis; or linear erythematous streaks, vesicles, and bullae on the forearms, hands, and face. Vesicles and bullae can be hemorrhagic in patients with pompholyxlike lesions.⁷

Some patients have been reported to present with facial angioedema; the clinical diagnosis of CD can be challenging when facial edema is more prominent than eczema.⁶ Furthermore, in a reported case of P obconica CD, the patient’s vesicular hand dermatitis became pustular and spread to the face.⁸

Allergy Testing

Patch testing is performed with synthetic primin to detect allergens of P obconica in patients who are sensitive to them, which can be useful because Primula dermatitis can have variable presentations and cases can be missed if patch testing is not performed.⁹ Diagnostic mimics—herpes simplex, pompholyx, seborrheic dermatitis, and scabies—should be considered before patch testing.⁷

Prevention and Treatment

Preventive Measures—Ideally, once CD occurs in response to P obconica, handling of and other exposure to the plant should be halted; thus, prevention becomes the mainstay of treatment. Alternatively, when exposure is a necessary occupational hazard, nitrile gloves should be worn; allergenicity can be decreased by overwatering or introducing more primin-free varieties.^3,10

Cultivating the plant outdoors during the winter in milder climates can potentially decrease sensitivity because allergen production is lowest during cold months and highest during summer.¹¹ Because P obconica is commonly grown indoors, allergenicity can persist year-round.

Pharmacotherapy—Drawing on experience treating CD caused by other plants, acute and chronic P obconica CD are primarily treated with a topical steroid or, if the face or genitals are affected, with a steroid-sparing agent, such as tacrolimus.¹² A cool compress of water, saline, or Burow solution (aluminum acetate in water) can help decrease acute inflammation, especially in the setting of vesiculation.¹³

Mild CD also can be treated with a barrier cream and lipid-rich moisturizer. Their effectiveness likely is due to increased hydration and aiding impaired skin-barrier repair.¹⁴

Some success in treating chronic CD also has been reported with psoralen plus UVA and UVB light therapy, which function as local immunosuppressants, thus decreasing inflammation.¹⁵

Final Thoughts

Contact dermatitis caused by P obconica is common in Europe but less common in the United States and therefore often is underrecognized. Avoiding contact with the plant should be strongly recommended to allergic persons. Primula obconica allergic CD can be treated with a topical steroid.

Etiology

Calcareous soils of central and southwest China are home to Primula obconica¹ (also known as German primrose and Libre Magenta).²Primula obconica was introduced to Europe in the 1880s, where it became a popular ornamental and decorative household plant (Figure).³ It also is a frequent resident of greenhouses.

Primula obconica is a member of the family Primulaceae, which comprises semi-evergreen perennials. The genus name Primula is derived from Latin meaning “first”; obconica refers to the conelike shape of the plant’s vivid, cerise-red flowers.

Allergens From P obconica

The allergens primin (2-methoxy-6-pentyl-1,4-benzoquinone) and miconidin (2-methoxy-6-pentyl-1, 4-dihydroxybenzene) have been isolated from P obconica stems, leaves, and flowers. Allergies to P obconica are much more commonly detected in Europe than in the United States because the plant is part of standard allergen screening in dermatology clinics in Europe.⁴ In a British patch test study of 234 patients with hand dermatitis, 34 displayed immediate or delayed sensitization to P obconica allergens.⁵ However, in another study, researchers who surveyed the incidence of P obconica allergic contact dermatitis (CD) in the United Kingdom found a notable decline in the number of primin-positive patch tests from 1995 to 2000, which likely was attributable to a decrease in the number of plant retailers who stocked P obconica and the availability of primin-free varieties from 50% of suppliers.³ Furthermore, a study in the United States of 567 consecutive patch tests that included primin as part of standard screening found only 1 positive reaction, suggesting that routine patch testing for P obconica in the United States would have a low yield unless the patient has a relevant history.⁴

Cutaneous Presentation

Clinical features of P obconica–induced dermatitis include fingertip dermatitis, as well as facial, hand, and forearm dermatitis.⁶ Patients typically present with lichenification and fissuring of the fingertips; fingertip vesicular dermatitis; or linear erythematous streaks, vesicles, and bullae on the forearms, hands, and face. Vesicles and bullae can be hemorrhagic in patients with pompholyxlike lesions.⁷

Some patients have been reported to present with facial angioedema; the clinical diagnosis of CD can be challenging when facial edema is more prominent than eczema.⁶ Furthermore, in a reported case of P obconica CD, the patient’s vesicular hand dermatitis became pustular and spread to the face.⁸

Allergy Testing

Patch testing is performed with synthetic primin to detect allergens of P obconica in patients who are sensitive to them, which can be useful because Primula dermatitis can have variable presentations and cases can be missed if patch testing is not performed.⁹ Diagnostic mimics—herpes simplex, pompholyx, seborrheic dermatitis, and scabies—should be considered before patch testing.⁷

Prevention and Treatment

Preventive Measures—Ideally, once CD occurs in response to P obconica, handling of and other exposure to the plant should be halted; thus, prevention becomes the mainstay of treatment. Alternatively, when exposure is a necessary occupational hazard, nitrile gloves should be worn; allergenicity can be decreased by overwatering or introducing more primin-free varieties.^3,10

Cultivating the plant outdoors during the winter in milder climates can potentially decrease sensitivity because allergen production is lowest during cold months and highest during summer.¹¹ Because P obconica is commonly grown indoors, allergenicity can persist year-round.

Pharmacotherapy—Drawing on experience treating CD caused by other plants, acute and chronic P obconica CD are primarily treated with a topical steroid or, if the face or genitals are affected, with a steroid-sparing agent, such as tacrolimus.¹² A cool compress of water, saline, or Burow solution (aluminum acetate in water) can help decrease acute inflammation, especially in the setting of vesiculation.¹³

Mild CD also can be treated with a barrier cream and lipid-rich moisturizer. Their effectiveness likely is due to increased hydration and aiding impaired skin-barrier repair.¹⁴

Some success in treating chronic CD also has been reported with psoralen plus UVA and UVB light therapy, which function as local immunosuppressants, thus decreasing inflammation.¹⁵

Final Thoughts

Contact dermatitis caused by P obconica is common in Europe but less common in the United States and therefore often is underrecognized. Avoiding contact with the plant should be strongly recommended to allergic persons. Primula obconica allergic CD can be treated with a topical steroid.

Technologies that allow people to monitor blood sugar and automate the administration of insulin have radically transformed the lives of patients – and children in particular – with type 1 diabetes. But the devices often come with a cost: Insulin pumps and continuous glucose monitors can irritate the skin at the points of contact, causing some people to stop using their pumps or monitors altogether.

Regular use of lipid-rich skin creams can reduce eczema in children who use insulin pumps and continuous glucose monitors to manage type 1 diabetes, Danish researchers reported last month. The article is currently undergoing peer review at The Lancet Diabetes and Endocrinology, and the authors said they hope their approach will deter more children from abandoning diabetes technology.

“A simple thing can actually change a lot,” said Anna Korsgaard Berg, MD, a pediatrician who specializes in diabetes care at Copenhagen University Hospital’s Steno Diabetes Center in Herlev, Denmark, and a coauthor of the new study. “Not all skin reactions can be solved by the skin care program, but it can help improve the issue.”

More than 1.5 million children and adolescents worldwide live with type 1 diabetes, a condition that requires continuous insulin infusion. Insulin pumps meet this need in many wealthier countries, and are often used in combination with sensors that measure a child’s glucose level. Both the American Diabetes Association and the International Society for Adolescent and Pediatric Diabetes recommend insulin pumps and continuous glucose monitors as core treatment tools.

Dr. Berg and colleagues, who have previously shown that as many as 90% of children who use these devices experience some kind of skin reaction, want to minimize the rate of such discomfort in hopes that fewer children stop using the devices. According to a 2014 study, 18% of people with type 1 diabetes who stopped using continuous glucose monitors did so because of skin irritation.
 

Lather on that lipid-rich lotion

Dr. Berg and colleagues studied 170 children and adolescents with type 1 diabetes (average age, 11 years) who use insulin pumps, continuous glucose monitors, or both. From March 2020 to July 2021, 112 children (55 girls) employed a skin care program developed for the study, while the other 58 (34 girls) did not receive any skin care advice.

The skin care group received instructions about how to gently insert and remove their insulin pumps or glucose monitors, to minimize skin damage. They also were told to avoid disinfectants such as alcohol, which can irritate skin. The children in this group used a cream containing 70% lipids to help rehydrate their skin, applying the salve each day a device was not inserted into their skin.

Eczema can be a real problem for kids who use insulin pumps and continuous glucose monitors to manage type 1 diabetes. Researchers found that regular use of lipid-rich skin creams can reduce its incidence.

Although insulin pumps and glucose monitors are kept in place for longer periods of time than they once were, Dr. Berg and colleagues noted, users do periodically remove them when bathing or when undergoing medical tests that involve x-rays. On days when the devices were not in place for a period of time, children in the skin care group were encouraged to follow the protocol.
 

Study results

One-third of children in the skin care group developed eczema or experienced a wound, compared with almost half of the children in the control group, according to the researchers. The absolute difference in developing eczema or wounds between the two groups was 12.9 % (95% confidence interval, –28.7% to 2.9%).

Children in the skin care group were much less likely to develop wounds, the researchers found, when they focused only on wounds and not eczema (odds ratio, 0.29, 95% CI, 0.12-0.68).

Dr. Berg said she would like to explore whether other techniques, such as a combination of patches, adhesives, or other lotions, yield even better results.

“Anything that can help people use technology more consistently is better for both quality of life and diabetes outcomes,” said Priya Prahalad, MD, a specialist in pediatric endocrinology and diabetes at Stanford Medicine Children’s Health in Palo Alto and Sunnyvale, Calif. 

Dr. Prahalad, who was not involved in the Danish study, said that although the sample sizes in the trial were relatively small, the data are “headed in the right direction.”

Pediatricians already recommend using moisturizing creams at the sites where pumps or glucose monitors are inserted into the skin, she noted. But the new study simply employed an especially moisturizing cream to mitigate skin damage.

Although one reason for skin irritation may be the repeated insertion and removal of devices, Dr. Berg and Dr. Prahalad stressed that the medical devices themselves may contain allergy-causing components. Device makers are not required to disclose what’s inside the boxes.

“I do not understand why the full content of a device is not by law mandatory to declare, when declaration by law is mandatory for many other products and drugs but not for medical devices,” Dr. Berg said.

Dr. Berg reports receiving lipid cream from Teva Pharmaceuticals and research support from Medtronic. Dr. Prahalad reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Technologies that allow people to monitor blood sugar and automate the administration of insulin have radically transformed the lives of patients – and children in particular – with type 1 diabetes. But the devices often come with a cost: Insulin pumps and continuous glucose monitors can irritate the skin at the points of contact, causing some people to stop using their pumps or monitors altogether.

Regular use of lipid-rich skin creams can reduce eczema in children who use insulin pumps and continuous glucose monitors to manage type 1 diabetes, Danish researchers reported last month. The article is currently undergoing peer review at The Lancet Diabetes and Endocrinology, and the authors said they hope their approach will deter more children from abandoning diabetes technology.

“A simple thing can actually change a lot,” said Anna Korsgaard Berg, MD, a pediatrician who specializes in diabetes care at Copenhagen University Hospital’s Steno Diabetes Center in Herlev, Denmark, and a coauthor of the new study. “Not all skin reactions can be solved by the skin care program, but it can help improve the issue.”

More than 1.5 million children and adolescents worldwide live with type 1 diabetes, a condition that requires continuous insulin infusion. Insulin pumps meet this need in many wealthier countries, and are often used in combination with sensors that measure a child’s glucose level. Both the American Diabetes Association and the International Society for Adolescent and Pediatric Diabetes recommend insulin pumps and continuous glucose monitors as core treatment tools.

Dr. Berg and colleagues, who have previously shown that as many as 90% of children who use these devices experience some kind of skin reaction, want to minimize the rate of such discomfort in hopes that fewer children stop using the devices. According to a 2014 study, 18% of people with type 1 diabetes who stopped using continuous glucose monitors did so because of skin irritation.
 

Lather on that lipid-rich lotion

Dr. Berg and colleagues studied 170 children and adolescents with type 1 diabetes (average age, 11 years) who use insulin pumps, continuous glucose monitors, or both. From March 2020 to July 2021, 112 children (55 girls) employed a skin care program developed for the study, while the other 58 (34 girls) did not receive any skin care advice.

The skin care group received instructions about how to gently insert and remove their insulin pumps or glucose monitors, to minimize skin damage. They also were told to avoid disinfectants such as alcohol, which can irritate skin. The children in this group used a cream containing 70% lipids to help rehydrate their skin, applying the salve each day a device was not inserted into their skin.

Eczema can be a real problem for kids who use insulin pumps and continuous glucose monitors to manage type 1 diabetes. Researchers found that regular use of lipid-rich skin creams can reduce its incidence.

Although insulin pumps and glucose monitors are kept in place for longer periods of time than they once were, Dr. Berg and colleagues noted, users do periodically remove them when bathing or when undergoing medical tests that involve x-rays. On days when the devices were not in place for a period of time, children in the skin care group were encouraged to follow the protocol.
 

Study results

One-third of children in the skin care group developed eczema or experienced a wound, compared with almost half of the children in the control group, according to the researchers. The absolute difference in developing eczema or wounds between the two groups was 12.9 % (95% confidence interval, –28.7% to 2.9%).

Children in the skin care group were much less likely to develop wounds, the researchers found, when they focused only on wounds and not eczema (odds ratio, 0.29, 95% CI, 0.12-0.68).

Dr. Berg said she would like to explore whether other techniques, such as a combination of patches, adhesives, or other lotions, yield even better results.

“Anything that can help people use technology more consistently is better for both quality of life and diabetes outcomes,” said Priya Prahalad, MD, a specialist in pediatric endocrinology and diabetes at Stanford Medicine Children’s Health in Palo Alto and Sunnyvale, Calif. 

Dr. Prahalad, who was not involved in the Danish study, said that although the sample sizes in the trial were relatively small, the data are “headed in the right direction.”

Pediatricians already recommend using moisturizing creams at the sites where pumps or glucose monitors are inserted into the skin, she noted. But the new study simply employed an especially moisturizing cream to mitigate skin damage.

Although one reason for skin irritation may be the repeated insertion and removal of devices, Dr. Berg and Dr. Prahalad stressed that the medical devices themselves may contain allergy-causing components. Device makers are not required to disclose what’s inside the boxes.

“I do not understand why the full content of a device is not by law mandatory to declare, when declaration by law is mandatory for many other products and drugs but not for medical devices,” Dr. Berg said.

Dr. Berg reports receiving lipid cream from Teva Pharmaceuticals and research support from Medtronic. Dr. Prahalad reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Technologies that allow people to monitor blood sugar and automate the administration of insulin have radically transformed the lives of patients – and children in particular – with type 1 diabetes. But the devices often come with a cost: Insulin pumps and continuous glucose monitors can irritate the skin at the points of contact, causing some people to stop using their pumps or monitors altogether.

Regular use of lipid-rich skin creams can reduce eczema in children who use insulin pumps and continuous glucose monitors to manage type 1 diabetes, Danish researchers reported last month. The article is currently undergoing peer review at The Lancet Diabetes and Endocrinology, and the authors said they hope their approach will deter more children from abandoning diabetes technology.

“A simple thing can actually change a lot,” said Anna Korsgaard Berg, MD, a pediatrician who specializes in diabetes care at Copenhagen University Hospital’s Steno Diabetes Center in Herlev, Denmark, and a coauthor of the new study. “Not all skin reactions can be solved by the skin care program, but it can help improve the issue.”

More than 1.5 million children and adolescents worldwide live with type 1 diabetes, a condition that requires continuous insulin infusion. Insulin pumps meet this need in many wealthier countries, and are often used in combination with sensors that measure a child’s glucose level. Both the American Diabetes Association and the International Society for Adolescent and Pediatric Diabetes recommend insulin pumps and continuous glucose monitors as core treatment tools.

Dr. Berg and colleagues, who have previously shown that as many as 90% of children who use these devices experience some kind of skin reaction, want to minimize the rate of such discomfort in hopes that fewer children stop using the devices. According to a 2014 study, 18% of people with type 1 diabetes who stopped using continuous glucose monitors did so because of skin irritation.
 

Lather on that lipid-rich lotion

Dr. Berg and colleagues studied 170 children and adolescents with type 1 diabetes (average age, 11 years) who use insulin pumps, continuous glucose monitors, or both. From March 2020 to July 2021, 112 children (55 girls) employed a skin care program developed for the study, while the other 58 (34 girls) did not receive any skin care advice.

The skin care group received instructions about how to gently insert and remove their insulin pumps or glucose monitors, to minimize skin damage. They also were told to avoid disinfectants such as alcohol, which can irritate skin. The children in this group used a cream containing 70% lipids to help rehydrate their skin, applying the salve each day a device was not inserted into their skin.

Eczema can be a real problem for kids who use insulin pumps and continuous glucose monitors to manage type 1 diabetes. Researchers found that regular use of lipid-rich skin creams can reduce its incidence.

Although insulin pumps and glucose monitors are kept in place for longer periods of time than they once were, Dr. Berg and colleagues noted, users do periodically remove them when bathing or when undergoing medical tests that involve x-rays. On days when the devices were not in place for a period of time, children in the skin care group were encouraged to follow the protocol.
 

Study results

One-third of children in the skin care group developed eczema or experienced a wound, compared with almost half of the children in the control group, according to the researchers. The absolute difference in developing eczema or wounds between the two groups was 12.9 % (95% confidence interval, –28.7% to 2.9%).

Children in the skin care group were much less likely to develop wounds, the researchers found, when they focused only on wounds and not eczema (odds ratio, 0.29, 95% CI, 0.12-0.68).

Dr. Berg said she would like to explore whether other techniques, such as a combination of patches, adhesives, or other lotions, yield even better results.

“Anything that can help people use technology more consistently is better for both quality of life and diabetes outcomes,” said Priya Prahalad, MD, a specialist in pediatric endocrinology and diabetes at Stanford Medicine Children’s Health in Palo Alto and Sunnyvale, Calif. 

Dr. Prahalad, who was not involved in the Danish study, said that although the sample sizes in the trial were relatively small, the data are “headed in the right direction.”

Pediatricians already recommend using moisturizing creams at the sites where pumps or glucose monitors are inserted into the skin, she noted. But the new study simply employed an especially moisturizing cream to mitigate skin damage.

Although one reason for skin irritation may be the repeated insertion and removal of devices, Dr. Berg and Dr. Prahalad stressed that the medical devices themselves may contain allergy-causing components. Device makers are not required to disclose what’s inside the boxes.

“I do not understand why the full content of a device is not by law mandatory to declare, when declaration by law is mandatory for many other products and drugs but not for medical devices,” Dr. Berg said.

Dr. Berg reports receiving lipid cream from Teva Pharmaceuticals and research support from Medtronic. Dr. Prahalad reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The prevalence of contact allergy triggered by a common product preservative, isothiazolinone, has decreased in Europe while it has increased in North America, a trend that is likely driven by regulatory differences, a retrospective cohort study suggests.

“Between 2009 to 2018, the global burden of isothiazolinone allergy showed divergent trends between North American and European countries,” lead study author Margo J. Reeder, MD, of the University of Wisconsin in Madison and her colleagues write. The study was published online in JAMA Dermatology.

Isothiazolinone contact allergy peaked in Europe in 2013-2014 before gradually decreasing, they found. The prevalence of isothiazolinone allergy steadily increased in North America during the study period. “Earlier and more stringent regulation of MI [methylisothiazolinone] in Europe is associated with these divergent trends,” they write.
 

Common ingredients worldwide

Isothiazolinone preservatives, which are added to personal and industrial products, cause allergic contact dermatitis worldwide, the authors write. The preservatives are found in a wide range of leave-on and rinse-off water-based personal care products, such as shampoo and other hair products, dishwashing liquid, face cream, body lotion, shower gel, liquid soap, and wet wipes, as well as in water-based paint.

A mixture of methylchloroisothiazolinone (MCI) and MI has been used to prevent microbial growth in products since the 1980s. In 2005, U.S. and European regulators approved MI alone at higher concentrations as a preservative in personal care products. Coupled with consumer concerns about other preservatives, such as parabens (a rare allergen), use of MI in personal care products increased, the authors write.

Subsequently, researchers reported a global increase in the prevalence of contact allergy to isothiazolinones, the authors write. Regulatory restrictions on MI in personal care products were implemented in 2013 in Europe and in 2015 in Canada but not in the United States.
 

Patch test data reveal latest trends

To compare prevalence trends of allergic contact allergy to MI and sensitization to the MCI/MI mixture in North America and in Europe, Dr. Reeder and her colleagues compared the prevalence of positive patch test reactions to MCI/MI and to MI alone in North America and in Europe between 2009 and 2018.

They analyzed data from the North American Contact Dermatitis Group (NACDG), the European Surveillance System on Contact Allergies (ESSCA), and the Information Network of Departments of Dermatology (IVDK) in 2-year intervals. The data came from patients who had been patch tested at referral patch test clinics in North America and Europe.

Over the decade, the study sites conducted patch testing for 226,161 patients for MCI/MI and 118,779 for MI. Most data came from Europe. The researchers found the following:

• In Europe, isothiazolinone allergy peaked in 2013 and 2014; MCI/MI positivity reached 7.6% (ESSCA) and 5.4% (IVDK) before decreasing to 4.4% (ESSCA) and 3.2% (IVDK) in 2017-2018.
• In North America, MCI/MI positivity rose steadily from 2.5% in 2009-2010 to 10.8% in 2017-2018.
• In Europe, there were 5.5% (ESSCA) and 3.4% (IVDK) positive reactions to MI, compared with 15% (NACDG) in North America in 2017-2018.

Divergent contact allergy trends linked to regulatory approaches

The downward trend of isothiazolinone allergy in Europe after its peak in 2013 and 2014 may have been due in part, the authors explain, to a memo released in 2013 by Cosmetics Europe after it and the European Society of Contact Dermatitis reviewed reports of increased contact allergy to MI. The memo urged companies to remove MI from leave-on products.

Later that year, the European Union’s Scientific Committee on Consumer Safety advised omitting MI from leave-on consumer personal care products and moved to restrict the ingredient in rinse-off products to less than 15 ppm. The recommendation took effect in 2015.

That year, Canada banned the use of MCI/MI in leave-on products but allowed MI alone in leave-on products until 2018. The total concentration of MI and MCI in wash-off products was limited to less than 15 ppm.

The authors add that, to their knowledge, the U.S. government does not restrict the use of MCI/MI or MI.
 

Policy implications for contact allergy

MI is still widely used in “countless products,” including shampoos, skin cleansers, dishwashing and laundry detergents, paints, and adhesives, Daniel W. Shaw, MD, associate professor of dermatology at the University of California, San Diego, told this news organization by email.

“Exact figures between the U.S. and Europe are difficult to compare due to differing patch test concentrations, but the overall trends strongly suggest that stricter and earlier regulation in Europe resulted in lower MI allergy prevalence there than in the U.S.,” added Dr. Shaw, who was not involved in the study.

Steven R. Feldman, MD, PhD, professor of dermatology at Wake Forest University in Winston-Salem, N.C., said by email that accurate information on allergic reaction prevalence is difficult to find.

“The NACDG, ESSCA, and IVDK databases may contain the best data available, but the data depend on people who get patch tested and are not directly informative of the allergy rates in the general population,” added Dr. Feldman, who was not involved in the study.

“The great majority of people in the population may not be allergic,” he said. “For those with itchy rashes, getting patch tested or avoiding products with preservatives may be prudent. Broad regulations, however, should consider the overall risks and benefits in the population, and this particular study does not fully capture those issues.”

“This study shows that government regulations are important to limit consumer exposure to common allergens, especially to the concentrations used in personal care products,” Kelly Tyler, MD, associate professor of dermatology at the Ohio State University Wexner Medical Center in Columbus, noted by email. She was not involved in the study.

She advised clinicians to ask their patients who may have allergic contact dermatitis whether they have been exposed to products containing these compounds.

“All personal care products in the store contain preservatives, and their maximum concentrations should be limited,” she advised. “The Expert Panel for Cosmetic Ingredient Safety should establish stricter guidelines for MI use in personal care products, especially given the findings of this study.”
 

Has MI contact allergy in North America peaked?

“In the U.S., MI has not been banned from leave-on skin-care products, but recently, its use has markedly decreased,” Dr. Shaw commented. “Hopefully, the prevalence of MI contact allergy will also begin to decrease.”

New evidence is promising. In a related study published online in Dermatology, Joel G. DeKoven, MD, MHSc, FRCPC, of the University of Toronto and his colleagues reported the NACDG 2019-2020 patch test results for MI in North America. They found that 13.8% of patients tested positive for MI.

“For the first time, MI positivity did not increase between reporting periods,” they conclude. “The epidemic of MI contact allergy in North America may have reached a plateau.”

Information regarding funding for the study was not provided. Dr. Reeder has financial relationships with the American Contact Dermatitis Society and a publishing company. Several coauthors have financial relationships with the pharmaceutical industry. Dr. Tyler, Dr. Shaw, and Dr. Feldman report no relevant financial relationship.

A version of this article first appeared on Medscape.com.

The prevalence of contact allergy triggered by a common product preservative, isothiazolinone, has decreased in Europe while it has increased in North America, a trend that is likely driven by regulatory differences, a retrospective cohort study suggests.

“Between 2009 to 2018, the global burden of isothiazolinone allergy showed divergent trends between North American and European countries,” lead study author Margo J. Reeder, MD, of the University of Wisconsin in Madison and her colleagues write. The study was published online in JAMA Dermatology.

Isothiazolinone contact allergy peaked in Europe in 2013-2014 before gradually decreasing, they found. The prevalence of isothiazolinone allergy steadily increased in North America during the study period. “Earlier and more stringent regulation of MI [methylisothiazolinone] in Europe is associated with these divergent trends,” they write.
 

Common ingredients worldwide

Isothiazolinone preservatives, which are added to personal and industrial products, cause allergic contact dermatitis worldwide, the authors write. The preservatives are found in a wide range of leave-on and rinse-off water-based personal care products, such as shampoo and other hair products, dishwashing liquid, face cream, body lotion, shower gel, liquid soap, and wet wipes, as well as in water-based paint.

A mixture of methylchloroisothiazolinone (MCI) and MI has been used to prevent microbial growth in products since the 1980s. In 2005, U.S. and European regulators approved MI alone at higher concentrations as a preservative in personal care products. Coupled with consumer concerns about other preservatives, such as parabens (a rare allergen), use of MI in personal care products increased, the authors write.

Subsequently, researchers reported a global increase in the prevalence of contact allergy to isothiazolinones, the authors write. Regulatory restrictions on MI in personal care products were implemented in 2013 in Europe and in 2015 in Canada but not in the United States.
 

Patch test data reveal latest trends

To compare prevalence trends of allergic contact allergy to MI and sensitization to the MCI/MI mixture in North America and in Europe, Dr. Reeder and her colleagues compared the prevalence of positive patch test reactions to MCI/MI and to MI alone in North America and in Europe between 2009 and 2018.

They analyzed data from the North American Contact Dermatitis Group (NACDG), the European Surveillance System on Contact Allergies (ESSCA), and the Information Network of Departments of Dermatology (IVDK) in 2-year intervals. The data came from patients who had been patch tested at referral patch test clinics in North America and Europe.

Over the decade, the study sites conducted patch testing for 226,161 patients for MCI/MI and 118,779 for MI. Most data came from Europe. The researchers found the following:

• In Europe, isothiazolinone allergy peaked in 2013 and 2014; MCI/MI positivity reached 7.6% (ESSCA) and 5.4% (IVDK) before decreasing to 4.4% (ESSCA) and 3.2% (IVDK) in 2017-2018.
• In North America, MCI/MI positivity rose steadily from 2.5% in 2009-2010 to 10.8% in 2017-2018.
• In Europe, there were 5.5% (ESSCA) and 3.4% (IVDK) positive reactions to MI, compared with 15% (NACDG) in North America in 2017-2018.

Divergent contact allergy trends linked to regulatory approaches

The downward trend of isothiazolinone allergy in Europe after its peak in 2013 and 2014 may have been due in part, the authors explain, to a memo released in 2013 by Cosmetics Europe after it and the European Society of Contact Dermatitis reviewed reports of increased contact allergy to MI. The memo urged companies to remove MI from leave-on products.

Later that year, the European Union’s Scientific Committee on Consumer Safety advised omitting MI from leave-on consumer personal care products and moved to restrict the ingredient in rinse-off products to less than 15 ppm. The recommendation took effect in 2015.

That year, Canada banned the use of MCI/MI in leave-on products but allowed MI alone in leave-on products until 2018. The total concentration of MI and MCI in wash-off products was limited to less than 15 ppm.

The authors add that, to their knowledge, the U.S. government does not restrict the use of MCI/MI or MI.
 

Policy implications for contact allergy

MI is still widely used in “countless products,” including shampoos, skin cleansers, dishwashing and laundry detergents, paints, and adhesives, Daniel W. Shaw, MD, associate professor of dermatology at the University of California, San Diego, told this news organization by email.

“Exact figures between the U.S. and Europe are difficult to compare due to differing patch test concentrations, but the overall trends strongly suggest that stricter and earlier regulation in Europe resulted in lower MI allergy prevalence there than in the U.S.,” added Dr. Shaw, who was not involved in the study.

Steven R. Feldman, MD, PhD, professor of dermatology at Wake Forest University in Winston-Salem, N.C., said by email that accurate information on allergic reaction prevalence is difficult to find.

“The NACDG, ESSCA, and IVDK databases may contain the best data available, but the data depend on people who get patch tested and are not directly informative of the allergy rates in the general population,” added Dr. Feldman, who was not involved in the study.

“The great majority of people in the population may not be allergic,” he said. “For those with itchy rashes, getting patch tested or avoiding products with preservatives may be prudent. Broad regulations, however, should consider the overall risks and benefits in the population, and this particular study does not fully capture those issues.”

“This study shows that government regulations are important to limit consumer exposure to common allergens, especially to the concentrations used in personal care products,” Kelly Tyler, MD, associate professor of dermatology at the Ohio State University Wexner Medical Center in Columbus, noted by email. She was not involved in the study.

She advised clinicians to ask their patients who may have allergic contact dermatitis whether they have been exposed to products containing these compounds.

“All personal care products in the store contain preservatives, and their maximum concentrations should be limited,” she advised. “The Expert Panel for Cosmetic Ingredient Safety should establish stricter guidelines for MI use in personal care products, especially given the findings of this study.”
 

Has MI contact allergy in North America peaked?

“In the U.S., MI has not been banned from leave-on skin-care products, but recently, its use has markedly decreased,” Dr. Shaw commented. “Hopefully, the prevalence of MI contact allergy will also begin to decrease.”

New evidence is promising. In a related study published online in Dermatology, Joel G. DeKoven, MD, MHSc, FRCPC, of the University of Toronto and his colleagues reported the NACDG 2019-2020 patch test results for MI in North America. They found that 13.8% of patients tested positive for MI.

“For the first time, MI positivity did not increase between reporting periods,” they conclude. “The epidemic of MI contact allergy in North America may have reached a plateau.”

Information regarding funding for the study was not provided. Dr. Reeder has financial relationships with the American Contact Dermatitis Society and a publishing company. Several coauthors have financial relationships with the pharmaceutical industry. Dr. Tyler, Dr. Shaw, and Dr. Feldman report no relevant financial relationship.

A version of this article first appeared on Medscape.com.

The prevalence of contact allergy triggered by a common product preservative, isothiazolinone, has decreased in Europe while it has increased in North America, a trend that is likely driven by regulatory differences, a retrospective cohort study suggests.

“Between 2009 to 2018, the global burden of isothiazolinone allergy showed divergent trends between North American and European countries,” lead study author Margo J. Reeder, MD, of the University of Wisconsin in Madison and her colleagues write. The study was published online in JAMA Dermatology.

Isothiazolinone contact allergy peaked in Europe in 2013-2014 before gradually decreasing, they found. The prevalence of isothiazolinone allergy steadily increased in North America during the study period. “Earlier and more stringent regulation of MI [methylisothiazolinone] in Europe is associated with these divergent trends,” they write.
 

Common ingredients worldwide

Isothiazolinone preservatives, which are added to personal and industrial products, cause allergic contact dermatitis worldwide, the authors write. The preservatives are found in a wide range of leave-on and rinse-off water-based personal care products, such as shampoo and other hair products, dishwashing liquid, face cream, body lotion, shower gel, liquid soap, and wet wipes, as well as in water-based paint.

A mixture of methylchloroisothiazolinone (MCI) and MI has been used to prevent microbial growth in products since the 1980s. In 2005, U.S. and European regulators approved MI alone at higher concentrations as a preservative in personal care products. Coupled with consumer concerns about other preservatives, such as parabens (a rare allergen), use of MI in personal care products increased, the authors write.

Subsequently, researchers reported a global increase in the prevalence of contact allergy to isothiazolinones, the authors write. Regulatory restrictions on MI in personal care products were implemented in 2013 in Europe and in 2015 in Canada but not in the United States.
 

Patch test data reveal latest trends

To compare prevalence trends of allergic contact allergy to MI and sensitization to the MCI/MI mixture in North America and in Europe, Dr. Reeder and her colleagues compared the prevalence of positive patch test reactions to MCI/MI and to MI alone in North America and in Europe between 2009 and 2018.

They analyzed data from the North American Contact Dermatitis Group (NACDG), the European Surveillance System on Contact Allergies (ESSCA), and the Information Network of Departments of Dermatology (IVDK) in 2-year intervals. The data came from patients who had been patch tested at referral patch test clinics in North America and Europe.

Over the decade, the study sites conducted patch testing for 226,161 patients for MCI/MI and 118,779 for MI. Most data came from Europe. The researchers found the following:

• In Europe, isothiazolinone allergy peaked in 2013 and 2014; MCI/MI positivity reached 7.6% (ESSCA) and 5.4% (IVDK) before decreasing to 4.4% (ESSCA) and 3.2% (IVDK) in 2017-2018.
• In North America, MCI/MI positivity rose steadily from 2.5% in 2009-2010 to 10.8% in 2017-2018.
• In Europe, there were 5.5% (ESSCA) and 3.4% (IVDK) positive reactions to MI, compared with 15% (NACDG) in North America in 2017-2018.

Divergent contact allergy trends linked to regulatory approaches

The downward trend of isothiazolinone allergy in Europe after its peak in 2013 and 2014 may have been due in part, the authors explain, to a memo released in 2013 by Cosmetics Europe after it and the European Society of Contact Dermatitis reviewed reports of increased contact allergy to MI. The memo urged companies to remove MI from leave-on products.

Later that year, the European Union’s Scientific Committee on Consumer Safety advised omitting MI from leave-on consumer personal care products and moved to restrict the ingredient in rinse-off products to less than 15 ppm. The recommendation took effect in 2015.

That year, Canada banned the use of MCI/MI in leave-on products but allowed MI alone in leave-on products until 2018. The total concentration of MI and MCI in wash-off products was limited to less than 15 ppm.

The authors add that, to their knowledge, the U.S. government does not restrict the use of MCI/MI or MI.
 

Policy implications for contact allergy

MI is still widely used in “countless products,” including shampoos, skin cleansers, dishwashing and laundry detergents, paints, and adhesives, Daniel W. Shaw, MD, associate professor of dermatology at the University of California, San Diego, told this news organization by email.

“Exact figures between the U.S. and Europe are difficult to compare due to differing patch test concentrations, but the overall trends strongly suggest that stricter and earlier regulation in Europe resulted in lower MI allergy prevalence there than in the U.S.,” added Dr. Shaw, who was not involved in the study.

Steven R. Feldman, MD, PhD, professor of dermatology at Wake Forest University in Winston-Salem, N.C., said by email that accurate information on allergic reaction prevalence is difficult to find.

“The NACDG, ESSCA, and IVDK databases may contain the best data available, but the data depend on people who get patch tested and are not directly informative of the allergy rates in the general population,” added Dr. Feldman, who was not involved in the study.

“The great majority of people in the population may not be allergic,” he said. “For those with itchy rashes, getting patch tested or avoiding products with preservatives may be prudent. Broad regulations, however, should consider the overall risks and benefits in the population, and this particular study does not fully capture those issues.”

“This study shows that government regulations are important to limit consumer exposure to common allergens, especially to the concentrations used in personal care products,” Kelly Tyler, MD, associate professor of dermatology at the Ohio State University Wexner Medical Center in Columbus, noted by email. She was not involved in the study.

She advised clinicians to ask their patients who may have allergic contact dermatitis whether they have been exposed to products containing these compounds.

“All personal care products in the store contain preservatives, and their maximum concentrations should be limited,” she advised. “The Expert Panel for Cosmetic Ingredient Safety should establish stricter guidelines for MI use in personal care products, especially given the findings of this study.”
 

Has MI contact allergy in North America peaked?

“In the U.S., MI has not been banned from leave-on skin-care products, but recently, its use has markedly decreased,” Dr. Shaw commented. “Hopefully, the prevalence of MI contact allergy will also begin to decrease.”

New evidence is promising. In a related study published online in Dermatology, Joel G. DeKoven, MD, MHSc, FRCPC, of the University of Toronto and his colleagues reported the NACDG 2019-2020 patch test results for MI in North America. They found that 13.8% of patients tested positive for MI.

“For the first time, MI positivity did not increase between reporting periods,” they conclude. “The epidemic of MI contact allergy in North America may have reached a plateau.”

Information regarding funding for the study was not provided. Dr. Reeder has financial relationships with the American Contact Dermatitis Society and a publishing company. Several coauthors have financial relationships with the pharmaceutical industry. Dr. Tyler, Dr. Shaw, and Dr. Feldman report no relevant financial relationship.

A version of this article first appeared on Medscape.com.

Allergic contact dermatitis (ACD) is a delayed type IV hypersensitivity reaction that usually manifests with eczematous lesions within hours to days after exposure to a contact allergen. The primary treatment of ACD consists of allergen avoidance, but medications also may be necessary to manage symptoms, particularly in cases where avoidance alone does not lead to resolution of dermatitis. At present, no medical therapies are explicitly approved for use in the management of ACD. Janus kinase (JAK) inhibitors are a class of small molecule inhibitors that are used for the treatment of a range of inflammatory diseases, such as rheumatoid arthritis and psoriatic arthritis. Several oral and topical JAK inhibitors also have recently been approved by the US Food and Drug Administration (FDA) for atopic dermatitis (AD). In this article, we discuss this important class of medications and the role that they may play in the off-label management of refractory ACD.

JAK/STAT Signaling Pathway

The JAK/signal transducer and activator of transcription (STAT) pathway plays a crucial role in many biologic processes. Notably, JAK/STAT signaling is involved in the development and regulation of the immune system.¹ The cascade begins when a particular transmembrane receptor binds a ligand, such as an interferon or interleukin.² Upon ligand binding, the receptor dimerizes or oligomerizes, bringing the relevant JAK proteins into close approximation to each other.³ This allows the JAK proteins to autophosphorylate or transphosphorylate.^2-4 Phosphorylation activates the JAK proteins and increases their kinase activity.³ In humans, there are 4 JAK proteins: JAK1, JAK2, JAK3, and tyrosine kinase 2.⁴ When activated, the JAK proteins phosphorylate specific tyrosine residues on the receptor, which creates a docking site for STAT proteins. After binding, the STAT proteins then are phosphorylated, leading to their dimerization and translocation to the nucleus.^2,3 Once in the nucleus, the STAT proteins act as transcription factors for target genes.³

JAK Inhibitors

Janus kinase inhibitors are immunomodulatory medications that work through inhibition of 1 or more of the JAK proteins in the JAK/STAT pathway. Through this mechanism, JAK inhibitors can impede the activity of proinflammatory cytokines and T cells.⁴ A brief overview of the commercially available JAK inhibitors in Europe, Japan, and the United States is provided in the Table.^5-29

Of the approved JAK inhibitors, more than 40% are indicated for AD. The first JAK inhibitor to be approved in the topical form was delgocitinib in 2020 in Japan.⁵ In a phase 3 trial, delgocitinib demonstrated significant reductions in modified Eczema Area and Severity Index (EASI) score (P<.001) as well as Peak Pruritus Numerical Rating Scale (P<.001) when compared with vehicle.³⁰ Topical ruxolitinib soon followed when its approval for AD was announced by the FDA in 2021.³¹ Results from 2 phase 3 trials found that significantly more patients achieved investigator global assessment (IGA) treatment success (P<.0001) and a significant reduction in itch as measured by the Peak Pruritus Numerical Rating Scale (P<.001) with topical ruxolitinib vs vehicle.³²

The first oral JAK inhibitor to attain approval for AD was baricitinib in Europe and Japan, but it is not currently approved for this indication in the United States by the FDA.^11,12,33 Consistent findings across phase 3 trials revealed that baricitinib was more effective at achieving IGA treatment success and improved EASI scores compared with placebo.³³

Upadacitinib, another oral JAK inhibitor, was subsequently approved for AD in Europe and Japan in 2021 and in the United States in early 2022.^5,9,26,27 Two replicate phase 3 trials demonstrated significant improvement in EASI score, itch, and quality of life with upadacitinib compared with placebo (P<.0001).³⁴ Abrocitinib was granted FDA approval for AD in the same time period, with phase 3 trials exhibiting greater responses in IGA and EASI scores vs placebo.³⁵

Potential for Use in ACD

Given the successful use of JAK inhibitors in the management of AD, there is optimism that these medications also may have potential application in ACD. Recent literature suggests that the 2 conditions may be more closely related mechanistically than previously understood. As a result, AD and ACD often are managed with the same therapeutic agents.³⁶

Although the exact etiology of ACD is still being elucidated, activation of T cells and cytokines plays an important role.³⁷ Notably, more than 40 cytokines exert their effects through the JAK/STAT signaling pathway, including IL-2, IL-6, IL-17, IL-22, and IFN-γ.^37,38 A study on nickel contact allergy revealed that JAK/STAT activation may regulate the balance between IL-12 and IL-23 and increase type 1 T-helper (T_H1) polarization.³⁹ Skin inflammation and chronic pruritus, which are major components of ACD, also are thought to be mediated in part by JAK signaling.^34,40

Animal studies have suggested that JAK inhibitors may show benefit in the management of ACD. Rats with oxazolone-induced ACD were found to have less swelling and epidermal thickening in the area of induced dermatitis after treatment with oral tofacitinib, comparable to the effects of cyclosporine. Tofacitinib was presumed to exert its effects through cytokine suppression, particularly that of IFN-γ, IL-22, and tumor necrosis factor α.⁴¹ In a separate study on mice with toluene-2,4-diisocyanate–induced ACD, both tofacitinib and another JAK inhibitor, oclacitinib, demonstrated inhibition of cytokine production, migration, and maturation of bone marrow–derived dendritic cells. Both topical and oral formulations of these 2 JAK inhibitors also were found to decrease scratching behavior; only the topicals improved ear thickness (used as a marker of skin inflammation), suggesting potential benefits to local application.⁴² In a murine model, oral delgocitinib also attenuated contact hypersensitivity via inhibition of antigen-specific T-cell proliferation and cytokine production.³⁷ Finally, in a randomized clinical trial conducted on dogs with allergic dermatitis (of which 10% were presumed to be from contact allergy), oral oclacitinib significantly reduced pruritus and clinical severity scores vs placebo (P<.0001).⁴³

There also are early clinical studies and case reports highlighting the effective use of JAK inhibitors in the management of ACD in humans. A 37-year-old man with occupational airborne ACD to Compositae saw full clearance of his dermatitis with daily oral abrocitinib after topical corticosteroids and dupilumab failed.⁴⁴ Another patient, a 57-year-old woman, had near-complete resolution of chronic Parthenium-induced airborne ACD after starting twice-daily oral tofacitinib. Allergen avoidance, as well as multiple medications, including topical and oral corticosteroids, topical calcineurin inhibitors, and azathioprine, previously failed in this patient.⁴⁵ Finally, a phase 2 study on patients with irritant and nonirritant chronic hand eczema found that significantly more patients achieved treatment success (as measured by the physician global assessment) with topical delgocitinib vs vehicle (P=.009).⁴⁶ Chronic hand eczema may be due to a variety of causes, including AD, irritant contact dermatitis, and ACD. Thus, these studies begin to highlight the potential role for JAK inhibitors in the management of refractory ACD.

Side Effects of JAK Inhibitors

The safety profile of JAK inhibitors must be taken into consideration. In general, topical JAK inhibitors are safe and well tolerated, with the majority of adverse events (AEs) seen in clinical trials considered mild or unrelated to the medication.^30,32 Nasopharyngitis, local skin infection, and acne were reported; a systematic review found no increased risk of AEs with topical JAK inhibitors compared with placebo.^30,32,47 Application-site reactions, a common concern among the existing topical calcineurin and phosphodiesterase 4 inhibitors, were rare (approximately 2% of patients).⁴⁷ The most frequent AEs seen in clinical trials of oral JAK inhibitors included acne, nasopharyngitis/upper respiratory tract infections, nausea, and headache.^33-35 Herpes simplex virus infection and worsening of AD also were seen. Although elevations in creatine phosphokinase levels were reported, patients often were asymptomatic and elevations were related to exercise or resolved without treatment interruption.^33-35

As a class, JAK inhibitors carry a boxed warning for serious infections, malignancy, major adverse cardiovascular events, thrombosis, and mortality. The FDA placed this label on JAK inhibitors because of the results of a randomized controlled trial of oral tofacitinib vs tumor necrosis factor α inhibitors in RA.^48,49 Notably, participants in the trial had to be 50 years or older and have at least 1 additional cardiovascular risk factor. Postmarket safety data are still being collected for patients with AD and other dermatologic conditions, but the findings of safety analyses have been reassuring to date.^50,51 Regular follow-up and routine laboratory monitoring are recommended for any patient started on an oral JAK inhibitor, which often includes monitoring of the complete blood cell count, comprehensive metabolic panel, and lipids, as well as baseline screening for tuberculosis and hepatitis.^52,53 For topical JAK inhibitors, no specific laboratory monitoring is recommended.

Finally, it must be considered that the challenges of off-label prescribing combined with high costs may limit access to JAK inhibitors for use in ACD.

Final Interpretation

Early investigations, including studies on animals and humans, suggest that JAK inhibitors are a promising option in the management of treatment-refractory ACD. Patients and providers should be aware of both the benefits and known side effects of JAK inhibitors prior to treatment initiation.

Allergic contact dermatitis (ACD) is a delayed type IV hypersensitivity reaction that usually manifests with eczematous lesions within hours to days after exposure to a contact allergen. The primary treatment of ACD consists of allergen avoidance, but medications also may be necessary to manage symptoms, particularly in cases where avoidance alone does not lead to resolution of dermatitis. At present, no medical therapies are explicitly approved for use in the management of ACD. Janus kinase (JAK) inhibitors are a class of small molecule inhibitors that are used for the treatment of a range of inflammatory diseases, such as rheumatoid arthritis and psoriatic arthritis. Several oral and topical JAK inhibitors also have recently been approved by the US Food and Drug Administration (FDA) for atopic dermatitis (AD). In this article, we discuss this important class of medications and the role that they may play in the off-label management of refractory ACD.

JAK/STAT Signaling Pathway

The JAK/signal transducer and activator of transcription (STAT) pathway plays a crucial role in many biologic processes. Notably, JAK/STAT signaling is involved in the development and regulation of the immune system.¹ The cascade begins when a particular transmembrane receptor binds a ligand, such as an interferon or interleukin.² Upon ligand binding, the receptor dimerizes or oligomerizes, bringing the relevant JAK proteins into close approximation to each other.³ This allows the JAK proteins to autophosphorylate or transphosphorylate.^2-4 Phosphorylation activates the JAK proteins and increases their kinase activity.³ In humans, there are 4 JAK proteins: JAK1, JAK2, JAK3, and tyrosine kinase 2.⁴ When activated, the JAK proteins phosphorylate specific tyrosine residues on the receptor, which creates a docking site for STAT proteins. After binding, the STAT proteins then are phosphorylated, leading to their dimerization and translocation to the nucleus.^2,3 Once in the nucleus, the STAT proteins act as transcription factors for target genes.³

JAK Inhibitors

Janus kinase inhibitors are immunomodulatory medications that work through inhibition of 1 or more of the JAK proteins in the JAK/STAT pathway. Through this mechanism, JAK inhibitors can impede the activity of proinflammatory cytokines and T cells.⁴ A brief overview of the commercially available JAK inhibitors in Europe, Japan, and the United States is provided in the Table.^5-29

Of the approved JAK inhibitors, more than 40% are indicated for AD. The first JAK inhibitor to be approved in the topical form was delgocitinib in 2020 in Japan.⁵ In a phase 3 trial, delgocitinib demonstrated significant reductions in modified Eczema Area and Severity Index (EASI) score (P<.001) as well as Peak Pruritus Numerical Rating Scale (P<.001) when compared with vehicle.³⁰ Topical ruxolitinib soon followed when its approval for AD was announced by the FDA in 2021.³¹ Results from 2 phase 3 trials found that significantly more patients achieved investigator global assessment (IGA) treatment success (P<.0001) and a significant reduction in itch as measured by the Peak Pruritus Numerical Rating Scale (P<.001) with topical ruxolitinib vs vehicle.³²

The first oral JAK inhibitor to attain approval for AD was baricitinib in Europe and Japan, but it is not currently approved for this indication in the United States by the FDA.^11,12,33 Consistent findings across phase 3 trials revealed that baricitinib was more effective at achieving IGA treatment success and improved EASI scores compared with placebo.³³

Upadacitinib, another oral JAK inhibitor, was subsequently approved for AD in Europe and Japan in 2021 and in the United States in early 2022.^5,9,26,27 Two replicate phase 3 trials demonstrated significant improvement in EASI score, itch, and quality of life with upadacitinib compared with placebo (P<.0001).³⁴ Abrocitinib was granted FDA approval for AD in the same time period, with phase 3 trials exhibiting greater responses in IGA and EASI scores vs placebo.³⁵

Potential for Use in ACD

Given the successful use of JAK inhibitors in the management of AD, there is optimism that these medications also may have potential application in ACD. Recent literature suggests that the 2 conditions may be more closely related mechanistically than previously understood. As a result, AD and ACD often are managed with the same therapeutic agents.³⁶

Although the exact etiology of ACD is still being elucidated, activation of T cells and cytokines plays an important role.³⁷ Notably, more than 40 cytokines exert their effects through the JAK/STAT signaling pathway, including IL-2, IL-6, IL-17, IL-22, and IFN-γ.^37,38 A study on nickel contact allergy revealed that JAK/STAT activation may regulate the balance between IL-12 and IL-23 and increase type 1 T-helper (T_H1) polarization.³⁹ Skin inflammation and chronic pruritus, which are major components of ACD, also are thought to be mediated in part by JAK signaling.^34,40

Animal studies have suggested that JAK inhibitors may show benefit in the management of ACD. Rats with oxazolone-induced ACD were found to have less swelling and epidermal thickening in the area of induced dermatitis after treatment with oral tofacitinib, comparable to the effects of cyclosporine. Tofacitinib was presumed to exert its effects through cytokine suppression, particularly that of IFN-γ, IL-22, and tumor necrosis factor α.⁴¹ In a separate study on mice with toluene-2,4-diisocyanate–induced ACD, both tofacitinib and another JAK inhibitor, oclacitinib, demonstrated inhibition of cytokine production, migration, and maturation of bone marrow–derived dendritic cells. Both topical and oral formulations of these 2 JAK inhibitors also were found to decrease scratching behavior; only the topicals improved ear thickness (used as a marker of skin inflammation), suggesting potential benefits to local application.⁴² In a murine model, oral delgocitinib also attenuated contact hypersensitivity via inhibition of antigen-specific T-cell proliferation and cytokine production.³⁷ Finally, in a randomized clinical trial conducted on dogs with allergic dermatitis (of which 10% were presumed to be from contact allergy), oral oclacitinib significantly reduced pruritus and clinical severity scores vs placebo (P<.0001).⁴³

There also are early clinical studies and case reports highlighting the effective use of JAK inhibitors in the management of ACD in humans. A 37-year-old man with occupational airborne ACD to Compositae saw full clearance of his dermatitis with daily oral abrocitinib after topical corticosteroids and dupilumab failed.⁴⁴ Another patient, a 57-year-old woman, had near-complete resolution of chronic Parthenium-induced airborne ACD after starting twice-daily oral tofacitinib. Allergen avoidance, as well as multiple medications, including topical and oral corticosteroids, topical calcineurin inhibitors, and azathioprine, previously failed in this patient.⁴⁵ Finally, a phase 2 study on patients with irritant and nonirritant chronic hand eczema found that significantly more patients achieved treatment success (as measured by the physician global assessment) with topical delgocitinib vs vehicle (P=.009).⁴⁶ Chronic hand eczema may be due to a variety of causes, including AD, irritant contact dermatitis, and ACD. Thus, these studies begin to highlight the potential role for JAK inhibitors in the management of refractory ACD.

Side Effects of JAK Inhibitors

The safety profile of JAK inhibitors must be taken into consideration. In general, topical JAK inhibitors are safe and well tolerated, with the majority of adverse events (AEs) seen in clinical trials considered mild or unrelated to the medication.^30,32 Nasopharyngitis, local skin infection, and acne were reported; a systematic review found no increased risk of AEs with topical JAK inhibitors compared with placebo.^30,32,47 Application-site reactions, a common concern among the existing topical calcineurin and phosphodiesterase 4 inhibitors, were rare (approximately 2% of patients).⁴⁷ The most frequent AEs seen in clinical trials of oral JAK inhibitors included acne, nasopharyngitis/upper respiratory tract infections, nausea, and headache.^33-35 Herpes simplex virus infection and worsening of AD also were seen. Although elevations in creatine phosphokinase levels were reported, patients often were asymptomatic and elevations were related to exercise or resolved without treatment interruption.^33-35

As a class, JAK inhibitors carry a boxed warning for serious infections, malignancy, major adverse cardiovascular events, thrombosis, and mortality. The FDA placed this label on JAK inhibitors because of the results of a randomized controlled trial of oral tofacitinib vs tumor necrosis factor α inhibitors in RA.^48,49 Notably, participants in the trial had to be 50 years or older and have at least 1 additional cardiovascular risk factor. Postmarket safety data are still being collected for patients with AD and other dermatologic conditions, but the findings of safety analyses have been reassuring to date.^50,51 Regular follow-up and routine laboratory monitoring are recommended for any patient started on an oral JAK inhibitor, which often includes monitoring of the complete blood cell count, comprehensive metabolic panel, and lipids, as well as baseline screening for tuberculosis and hepatitis.^52,53 For topical JAK inhibitors, no specific laboratory monitoring is recommended.

Finally, it must be considered that the challenges of off-label prescribing combined with high costs may limit access to JAK inhibitors for use in ACD.

Final Interpretation

Early investigations, including studies on animals and humans, suggest that JAK inhibitors are a promising option in the management of treatment-refractory ACD. Patients and providers should be aware of both the benefits and known side effects of JAK inhibitors prior to treatment initiation.

Allergic contact dermatitis (ACD) is a delayed type IV hypersensitivity reaction that usually manifests with eczematous lesions within hours to days after exposure to a contact allergen. The primary treatment of ACD consists of allergen avoidance, but medications also may be necessary to manage symptoms, particularly in cases where avoidance alone does not lead to resolution of dermatitis. At present, no medical therapies are explicitly approved for use in the management of ACD. Janus kinase (JAK) inhibitors are a class of small molecule inhibitors that are used for the treatment of a range of inflammatory diseases, such as rheumatoid arthritis and psoriatic arthritis. Several oral and topical JAK inhibitors also have recently been approved by the US Food and Drug Administration (FDA) for atopic dermatitis (AD). In this article, we discuss this important class of medications and the role that they may play in the off-label management of refractory ACD.

JAK/STAT Signaling Pathway

The JAK/signal transducer and activator of transcription (STAT) pathway plays a crucial role in many biologic processes. Notably, JAK/STAT signaling is involved in the development and regulation of the immune system.¹ The cascade begins when a particular transmembrane receptor binds a ligand, such as an interferon or interleukin.² Upon ligand binding, the receptor dimerizes or oligomerizes, bringing the relevant JAK proteins into close approximation to each other.³ This allows the JAK proteins to autophosphorylate or transphosphorylate.^2-4 Phosphorylation activates the JAK proteins and increases their kinase activity.³ In humans, there are 4 JAK proteins: JAK1, JAK2, JAK3, and tyrosine kinase 2.⁴ When activated, the JAK proteins phosphorylate specific tyrosine residues on the receptor, which creates a docking site for STAT proteins. After binding, the STAT proteins then are phosphorylated, leading to their dimerization and translocation to the nucleus.^2,3 Once in the nucleus, the STAT proteins act as transcription factors for target genes.³

JAK Inhibitors

Janus kinase inhibitors are immunomodulatory medications that work through inhibition of 1 or more of the JAK proteins in the JAK/STAT pathway. Through this mechanism, JAK inhibitors can impede the activity of proinflammatory cytokines and T cells.⁴ A brief overview of the commercially available JAK inhibitors in Europe, Japan, and the United States is provided in the Table.^5-29

Of the approved JAK inhibitors, more than 40% are indicated for AD. The first JAK inhibitor to be approved in the topical form was delgocitinib in 2020 in Japan.⁵ In a phase 3 trial, delgocitinib demonstrated significant reductions in modified Eczema Area and Severity Index (EASI) score (P<.001) as well as Peak Pruritus Numerical Rating Scale (P<.001) when compared with vehicle.³⁰ Topical ruxolitinib soon followed when its approval for AD was announced by the FDA in 2021.³¹ Results from 2 phase 3 trials found that significantly more patients achieved investigator global assessment (IGA) treatment success (P<.0001) and a significant reduction in itch as measured by the Peak Pruritus Numerical Rating Scale (P<.001) with topical ruxolitinib vs vehicle.³²

The first oral JAK inhibitor to attain approval for AD was baricitinib in Europe and Japan, but it is not currently approved for this indication in the United States by the FDA.^11,12,33 Consistent findings across phase 3 trials revealed that baricitinib was more effective at achieving IGA treatment success and improved EASI scores compared with placebo.³³

Upadacitinib, another oral JAK inhibitor, was subsequently approved for AD in Europe and Japan in 2021 and in the United States in early 2022.^5,9,26,27 Two replicate phase 3 trials demonstrated significant improvement in EASI score, itch, and quality of life with upadacitinib compared with placebo (P<.0001).³⁴ Abrocitinib was granted FDA approval for AD in the same time period, with phase 3 trials exhibiting greater responses in IGA and EASI scores vs placebo.³⁵

Potential for Use in ACD

Given the successful use of JAK inhibitors in the management of AD, there is optimism that these medications also may have potential application in ACD. Recent literature suggests that the 2 conditions may be more closely related mechanistically than previously understood. As a result, AD and ACD often are managed with the same therapeutic agents.³⁶

Although the exact etiology of ACD is still being elucidated, activation of T cells and cytokines plays an important role.³⁷ Notably, more than 40 cytokines exert their effects through the JAK/STAT signaling pathway, including IL-2, IL-6, IL-17, IL-22, and IFN-γ.^37,38 A study on nickel contact allergy revealed that JAK/STAT activation may regulate the balance between IL-12 and IL-23 and increase type 1 T-helper (T_H1) polarization.³⁹ Skin inflammation and chronic pruritus, which are major components of ACD, also are thought to be mediated in part by JAK signaling.^34,40

Animal studies have suggested that JAK inhibitors may show benefit in the management of ACD. Rats with oxazolone-induced ACD were found to have less swelling and epidermal thickening in the area of induced dermatitis after treatment with oral tofacitinib, comparable to the effects of cyclosporine. Tofacitinib was presumed to exert its effects through cytokine suppression, particularly that of IFN-γ, IL-22, and tumor necrosis factor α.⁴¹ In a separate study on mice with toluene-2,4-diisocyanate–induced ACD, both tofacitinib and another JAK inhibitor, oclacitinib, demonstrated inhibition of cytokine production, migration, and maturation of bone marrow–derived dendritic cells. Both topical and oral formulations of these 2 JAK inhibitors also were found to decrease scratching behavior; only the topicals improved ear thickness (used as a marker of skin inflammation), suggesting potential benefits to local application.⁴² In a murine model, oral delgocitinib also attenuated contact hypersensitivity via inhibition of antigen-specific T-cell proliferation and cytokine production.³⁷ Finally, in a randomized clinical trial conducted on dogs with allergic dermatitis (of which 10% were presumed to be from contact allergy), oral oclacitinib significantly reduced pruritus and clinical severity scores vs placebo (P<.0001).⁴³

There also are early clinical studies and case reports highlighting the effective use of JAK inhibitors in the management of ACD in humans. A 37-year-old man with occupational airborne ACD to Compositae saw full clearance of his dermatitis with daily oral abrocitinib after topical corticosteroids and dupilumab failed.⁴⁴ Another patient, a 57-year-old woman, had near-complete resolution of chronic Parthenium-induced airborne ACD after starting twice-daily oral tofacitinib. Allergen avoidance, as well as multiple medications, including topical and oral corticosteroids, topical calcineurin inhibitors, and azathioprine, previously failed in this patient.⁴⁵ Finally, a phase 2 study on patients with irritant and nonirritant chronic hand eczema found that significantly more patients achieved treatment success (as measured by the physician global assessment) with topical delgocitinib vs vehicle (P=.009).⁴⁶ Chronic hand eczema may be due to a variety of causes, including AD, irritant contact dermatitis, and ACD. Thus, these studies begin to highlight the potential role for JAK inhibitors in the management of refractory ACD.

Side Effects of JAK Inhibitors

The safety profile of JAK inhibitors must be taken into consideration. In general, topical JAK inhibitors are safe and well tolerated, with the majority of adverse events (AEs) seen in clinical trials considered mild or unrelated to the medication.^30,32 Nasopharyngitis, local skin infection, and acne were reported; a systematic review found no increased risk of AEs with topical JAK inhibitors compared with placebo.^30,32,47 Application-site reactions, a common concern among the existing topical calcineurin and phosphodiesterase 4 inhibitors, were rare (approximately 2% of patients).⁴⁷ The most frequent AEs seen in clinical trials of oral JAK inhibitors included acne, nasopharyngitis/upper respiratory tract infections, nausea, and headache.^33-35 Herpes simplex virus infection and worsening of AD also were seen. Although elevations in creatine phosphokinase levels were reported, patients often were asymptomatic and elevations were related to exercise or resolved without treatment interruption.^33-35

As a class, JAK inhibitors carry a boxed warning for serious infections, malignancy, major adverse cardiovascular events, thrombosis, and mortality. The FDA placed this label on JAK inhibitors because of the results of a randomized controlled trial of oral tofacitinib vs tumor necrosis factor α inhibitors in RA.^48,49 Notably, participants in the trial had to be 50 years or older and have at least 1 additional cardiovascular risk factor. Postmarket safety data are still being collected for patients with AD and other dermatologic conditions, but the findings of safety analyses have been reassuring to date.^50,51 Regular follow-up and routine laboratory monitoring are recommended for any patient started on an oral JAK inhibitor, which often includes monitoring of the complete blood cell count, comprehensive metabolic panel, and lipids, as well as baseline screening for tuberculosis and hepatitis.^52,53 For topical JAK inhibitors, no specific laboratory monitoring is recommended.

Finally, it must be considered that the challenges of off-label prescribing combined with high costs may limit access to JAK inhibitors for use in ACD.

Final Interpretation

Early investigations, including studies on animals and humans, suggest that JAK inhibitors are a promising option in the management of treatment-refractory ACD. Patients and providers should be aware of both the benefits and known side effects of JAK inhibitors prior to treatment initiation.

To the Editor:

Today’s geriatric population is the fastest growing in history. The National Institutes of Health predicts there will be over 1.5 billion individuals aged 65 years and older by the year 2050: 17% of the world’s population.¹ Pruritus—either acute or chronic (>6 weeks)—is defined as a sensory perception that leads to an intense desire to scratch.² Chronic pruritus is an increasing health concern that impacts quality of life within the geriatric population. Elderly patients have various risk factors for developing chronic itch, including aging skin, polypharmacy, and increased systemic comorbidities.^3-7

Although the therapeutic armamentarium for chronic itch continues to grow, health care providers often are hesitant to prescribe medications for geriatric patients because of comorbidities and potential drug-drug interactions. Novel biologic therapies now provide alternatives for this complex population. Dupilumab is a fully humanized, monoclonal antibody approved for treatment-resistant atopic dermatitis. This biologic prevents helper T-cell (T_H2) signaling, IL-4 and IL-13 release, and subsequent effector cell (eg, mast cell, eosinophil) activity.^8-10 The combined efficacy and safety of this medication has changed the treatment landscape of resistant atopic dermatitis. We present the use of dupilumab in a geriatric patient with severe and recalcitrant itch resistant to numerous topical and oral medications.

An 81-year-old man presented to the clinic with a long history of generalized pruritic rash. His medical history was significant for insulin-dependent type 2 diabetes mellitus (T2DM), hypertension, and renal cancer following a right nephrectomy. Laboratory results approximately 14 months prior to the visit revealed a blood urea nitrogen level of 31 mg/dL (reference range, 7–20 mg/dL), creatinine level of 2.20 mg/dL (reference range, 0.7–1.3 mg/dL), and glomerular filtration rate of 29 mL/min (reference range, 90–120 mL/min). Physical examination revealed numerous pink excoriated papules on the face, neck, trunk, and extremities. Lichenified plaques were present on both arms and legs. The patient received the diagnosis of severe atopic dermatitis with greater than 10% body surface area involvement. The investigator global assessment score was 4/4, indicating severe disease burden, and biopsy results reported spongiotic dermatitis. He proceeded to trial various topical corticosteroids, including hydrocortisone ointment 2.5%, betamethasone valerate ointment 0.01%, fluocinonide ointment 0.05%, and mupirocin ointment without benefit. Three subsequent courses of oral steroids failed to provide durable relief. At this point, the peak pruritus numerical rating scale (NRS) score was 7/10, indicating severe pruritus, with a negative impact on the patient’s quality of life and sleep.

Therapy was switched to tacrolimus acetonide ointment 0.1%, betamethasone dipropionate ointment 0.05%, and triamcinolone acetonide ointment 0.1%. Eleven days later, the patient denied experiencing any response to the topical regimen and sought alternative therapy for the itch and associated poor sleep; the NRS score was 10/10, indicating very severe pruritus. Prednisone 20 mg and doxepin 10 mg were initiated for symptom management until the intended transition to dupilumab. The patient began dupilumab with a loading dose of 600 mg, then 300 mg every other week thereafter. At 2- and 4-month follow-up, the patient reported notable relief in symptoms. The rash had improved, and the NRS score decreased from 10/10 to 3/10. He endorsed improved sleep and quality of life.

Pruritus may arise from a series of age-related mechanisms such as structural and chemical changes within the epidermis, underlying neuropathy, medication side effects, infection, malignancy, thyroid dysregulation, liver disease, and chronic kidney disease (CKD).^5,6,11 Identifying the underlying etiology often is difficult and involves a complete history and physical examination as well as an appropriate contextualized laboratory workup.

Our patient’s comorbid T2DM and renal disease may have contributed to the pruritus. Type 2 diabetes mellitus can cause diabetic neuropathy, a sequela known to lead to various complications, including pruritus. One study identified a 4-fold increase in pruritus in those with diabetic polyneuropathy compared with age-matched nondiabetics.^12,13 An additional study found that pruritus was present in 70% of patients with small fiber neuropathy.¹⁴ We needed to consider the role of our patient’s insulin-dependent T2DM and potential underlying neuropathy when addressing the pruritic symptoms.

Furthermore, our patient’s stage IV CKD and elevated urea level also may factor into the pruritus. The pathophysiology of CKD-associated pruritus (also referred to as uremic pruritus) remains poorly understood. Suggested mechanisms include immune-mediated neural inflammation and erroneous nociceptive-receptor activity.^15,16 Although uremic pruritus is appreciated primarily in late dialysis-dependent disease, research shows that a notable portion of those with lesser disease, similar to our patient, also experience a significant itch burden.¹⁷ Diminishing pruritus is difficult and often aided by management of the underlying renal disease.¹⁸

In addition to disease management, symptomatic treatment incorporates the use of emollients, corticosteroids, and antihistamines. Unfortunately, the clinical response in the elderly population to such regimens often is poor.¹⁹ Dupilumab is an optimistic therapeutic option for chronic pruritus. By inhibiting the IL-4α receptor found on helper T cells, this biologic inhibits T_H2 differentiation and subsequent inflammatory activity. One report identified an optimistic response to dupilumab in the management of uremic pruritus.²⁰ The remarkable improvement and absence of adverse effects in our patient confirmed the utility and safety of dupilumab in complex cases such as elderly patients with multiple comorbidities. Such relief may result from inhibition of proinflammatory cytokine activity as well as decreased afferent spinal cord itch stimuli.¹⁰ The positive results from this case cast a favorable outlook on the treatment of chronic itch in the complex geriatric population.

To the Editor:

Today’s geriatric population is the fastest growing in history. The National Institutes of Health predicts there will be over 1.5 billion individuals aged 65 years and older by the year 2050: 17% of the world’s population.¹ Pruritus—either acute or chronic (>6 weeks)—is defined as a sensory perception that leads to an intense desire to scratch.² Chronic pruritus is an increasing health concern that impacts quality of life within the geriatric population. Elderly patients have various risk factors for developing chronic itch, including aging skin, polypharmacy, and increased systemic comorbidities.^3-7

Although the therapeutic armamentarium for chronic itch continues to grow, health care providers often are hesitant to prescribe medications for geriatric patients because of comorbidities and potential drug-drug interactions. Novel biologic therapies now provide alternatives for this complex population. Dupilumab is a fully humanized, monoclonal antibody approved for treatment-resistant atopic dermatitis. This biologic prevents helper T-cell (T_H2) signaling, IL-4 and IL-13 release, and subsequent effector cell (eg, mast cell, eosinophil) activity.^8-10 The combined efficacy and safety of this medication has changed the treatment landscape of resistant atopic dermatitis. We present the use of dupilumab in a geriatric patient with severe and recalcitrant itch resistant to numerous topical and oral medications.

An 81-year-old man presented to the clinic with a long history of generalized pruritic rash. His medical history was significant for insulin-dependent type 2 diabetes mellitus (T2DM), hypertension, and renal cancer following a right nephrectomy. Laboratory results approximately 14 months prior to the visit revealed a blood urea nitrogen level of 31 mg/dL (reference range, 7–20 mg/dL), creatinine level of 2.20 mg/dL (reference range, 0.7–1.3 mg/dL), and glomerular filtration rate of 29 mL/min (reference range, 90–120 mL/min). Physical examination revealed numerous pink excoriated papules on the face, neck, trunk, and extremities. Lichenified plaques were present on both arms and legs. The patient received the diagnosis of severe atopic dermatitis with greater than 10% body surface area involvement. The investigator global assessment score was 4/4, indicating severe disease burden, and biopsy results reported spongiotic dermatitis. He proceeded to trial various topical corticosteroids, including hydrocortisone ointment 2.5%, betamethasone valerate ointment 0.01%, fluocinonide ointment 0.05%, and mupirocin ointment without benefit. Three subsequent courses of oral steroids failed to provide durable relief. At this point, the peak pruritus numerical rating scale (NRS) score was 7/10, indicating severe pruritus, with a negative impact on the patient’s quality of life and sleep.

Therapy was switched to tacrolimus acetonide ointment 0.1%, betamethasone dipropionate ointment 0.05%, and triamcinolone acetonide ointment 0.1%. Eleven days later, the patient denied experiencing any response to the topical regimen and sought alternative therapy for the itch and associated poor sleep; the NRS score was 10/10, indicating very severe pruritus. Prednisone 20 mg and doxepin 10 mg were initiated for symptom management until the intended transition to dupilumab. The patient began dupilumab with a loading dose of 600 mg, then 300 mg every other week thereafter. At 2- and 4-month follow-up, the patient reported notable relief in symptoms. The rash had improved, and the NRS score decreased from 10/10 to 3/10. He endorsed improved sleep and quality of life.

Pruritus may arise from a series of age-related mechanisms such as structural and chemical changes within the epidermis, underlying neuropathy, medication side effects, infection, malignancy, thyroid dysregulation, liver disease, and chronic kidney disease (CKD).^5,6,11 Identifying the underlying etiology often is difficult and involves a complete history and physical examination as well as an appropriate contextualized laboratory workup.

Our patient’s comorbid T2DM and renal disease may have contributed to the pruritus. Type 2 diabetes mellitus can cause diabetic neuropathy, a sequela known to lead to various complications, including pruritus. One study identified a 4-fold increase in pruritus in those with diabetic polyneuropathy compared with age-matched nondiabetics.^12,13 An additional study found that pruritus was present in 70% of patients with small fiber neuropathy.¹⁴ We needed to consider the role of our patient’s insulin-dependent T2DM and potential underlying neuropathy when addressing the pruritic symptoms.

Furthermore, our patient’s stage IV CKD and elevated urea level also may factor into the pruritus. The pathophysiology of CKD-associated pruritus (also referred to as uremic pruritus) remains poorly understood. Suggested mechanisms include immune-mediated neural inflammation and erroneous nociceptive-receptor activity.^15,16 Although uremic pruritus is appreciated primarily in late dialysis-dependent disease, research shows that a notable portion of those with lesser disease, similar to our patient, also experience a significant itch burden.¹⁷ Diminishing pruritus is difficult and often aided by management of the underlying renal disease.¹⁸

In addition to disease management, symptomatic treatment incorporates the use of emollients, corticosteroids, and antihistamines. Unfortunately, the clinical response in the elderly population to such regimens often is poor.¹⁹ Dupilumab is an optimistic therapeutic option for chronic pruritus. By inhibiting the IL-4α receptor found on helper T cells, this biologic inhibits T_H2 differentiation and subsequent inflammatory activity. One report identified an optimistic response to dupilumab in the management of uremic pruritus.²⁰ The remarkable improvement and absence of adverse effects in our patient confirmed the utility and safety of dupilumab in complex cases such as elderly patients with multiple comorbidities. Such relief may result from inhibition of proinflammatory cytokine activity as well as decreased afferent spinal cord itch stimuli.¹⁰ The positive results from this case cast a favorable outlook on the treatment of chronic itch in the complex geriatric population.

To the Editor:

Today’s geriatric population is the fastest growing in history. The National Institutes of Health predicts there will be over 1.5 billion individuals aged 65 years and older by the year 2050: 17% of the world’s population.¹ Pruritus—either acute or chronic (>6 weeks)—is defined as a sensory perception that leads to an intense desire to scratch.² Chronic pruritus is an increasing health concern that impacts quality of life within the geriatric population. Elderly patients have various risk factors for developing chronic itch, including aging skin, polypharmacy, and increased systemic comorbidities.^3-7

Although the therapeutic armamentarium for chronic itch continues to grow, health care providers often are hesitant to prescribe medications for geriatric patients because of comorbidities and potential drug-drug interactions. Novel biologic therapies now provide alternatives for this complex population. Dupilumab is a fully humanized, monoclonal antibody approved for treatment-resistant atopic dermatitis. This biologic prevents helper T-cell (T_H2) signaling, IL-4 and IL-13 release, and subsequent effector cell (eg, mast cell, eosinophil) activity.^8-10 The combined efficacy and safety of this medication has changed the treatment landscape of resistant atopic dermatitis. We present the use of dupilumab in a geriatric patient with severe and recalcitrant itch resistant to numerous topical and oral medications.

An 81-year-old man presented to the clinic with a long history of generalized pruritic rash. His medical history was significant for insulin-dependent type 2 diabetes mellitus (T2DM), hypertension, and renal cancer following a right nephrectomy. Laboratory results approximately 14 months prior to the visit revealed a blood urea nitrogen level of 31 mg/dL (reference range, 7–20 mg/dL), creatinine level of 2.20 mg/dL (reference range, 0.7–1.3 mg/dL), and glomerular filtration rate of 29 mL/min (reference range, 90–120 mL/min). Physical examination revealed numerous pink excoriated papules on the face, neck, trunk, and extremities. Lichenified plaques were present on both arms and legs. The patient received the diagnosis of severe atopic dermatitis with greater than 10% body surface area involvement. The investigator global assessment score was 4/4, indicating severe disease burden, and biopsy results reported spongiotic dermatitis. He proceeded to trial various topical corticosteroids, including hydrocortisone ointment 2.5%, betamethasone valerate ointment 0.01%, fluocinonide ointment 0.05%, and mupirocin ointment without benefit. Three subsequent courses of oral steroids failed to provide durable relief. At this point, the peak pruritus numerical rating scale (NRS) score was 7/10, indicating severe pruritus, with a negative impact on the patient’s quality of life and sleep.

Therapy was switched to tacrolimus acetonide ointment 0.1%, betamethasone dipropionate ointment 0.05%, and triamcinolone acetonide ointment 0.1%. Eleven days later, the patient denied experiencing any response to the topical regimen and sought alternative therapy for the itch and associated poor sleep; the NRS score was 10/10, indicating very severe pruritus. Prednisone 20 mg and doxepin 10 mg were initiated for symptom management until the intended transition to dupilumab. The patient began dupilumab with a loading dose of 600 mg, then 300 mg every other week thereafter. At 2- and 4-month follow-up, the patient reported notable relief in symptoms. The rash had improved, and the NRS score decreased from 10/10 to 3/10. He endorsed improved sleep and quality of life.

Pruritus may arise from a series of age-related mechanisms such as structural and chemical changes within the epidermis, underlying neuropathy, medication side effects, infection, malignancy, thyroid dysregulation, liver disease, and chronic kidney disease (CKD).^5,6,11 Identifying the underlying etiology often is difficult and involves a complete history and physical examination as well as an appropriate contextualized laboratory workup.

Our patient’s comorbid T2DM and renal disease may have contributed to the pruritus. Type 2 diabetes mellitus can cause diabetic neuropathy, a sequela known to lead to various complications, including pruritus. One study identified a 4-fold increase in pruritus in those with diabetic polyneuropathy compared with age-matched nondiabetics.^12,13 An additional study found that pruritus was present in 70% of patients with small fiber neuropathy.¹⁴ We needed to consider the role of our patient’s insulin-dependent T2DM and potential underlying neuropathy when addressing the pruritic symptoms.

Furthermore, our patient’s stage IV CKD and elevated urea level also may factor into the pruritus. The pathophysiology of CKD-associated pruritus (also referred to as uremic pruritus) remains poorly understood. Suggested mechanisms include immune-mediated neural inflammation and erroneous nociceptive-receptor activity.^15,16 Although uremic pruritus is appreciated primarily in late dialysis-dependent disease, research shows that a notable portion of those with lesser disease, similar to our patient, also experience a significant itch burden.¹⁷ Diminishing pruritus is difficult and often aided by management of the underlying renal disease.¹⁸

In addition to disease management, symptomatic treatment incorporates the use of emollients, corticosteroids, and antihistamines. Unfortunately, the clinical response in the elderly population to such regimens often is poor.¹⁹ Dupilumab is an optimistic therapeutic option for chronic pruritus. By inhibiting the IL-4α receptor found on helper T cells, this biologic inhibits T_H2 differentiation and subsequent inflammatory activity. One report identified an optimistic response to dupilumab in the management of uremic pruritus.²⁰ The remarkable improvement and absence of adverse effects in our patient confirmed the utility and safety of dupilumab in complex cases such as elderly patients with multiple comorbidities. Such relief may result from inhibition of proinflammatory cytokine activity as well as decreased afferent spinal cord itch stimuli.¹⁰ The positive results from this case cast a favorable outlook on the treatment of chronic itch in the complex geriatric population.

Hereditary alpha tryptasemia (HaT), an autosomal-dominant disorder of tryptase overproduction, was first described in 2014 by Lyons et al.¹ It has been associated with multiple dermatologic, allergic, gastrointestinal (GI) tract, neuropsychiatric, respiratory, autonomic, and connective tissue abnormalities. These multisystem concerns may include cutaneous flushing, chronic pruritus, urticaria, GI tract symptoms, arthralgia, and autonomic dysfunction.² The diverse symptoms and the recent discovery of HaT make recognition of this disorder challenging. Currently, it also is believed that HaT is associated with an elevated risk for anaphylaxis and is a biomarker for severe symptoms in disorders with increased mast cell burden such as mastocytosis.^3-5

Given the potential cutaneous manifestations and the fact that dermatologic symptoms may be the initial presentation of HaT, awareness and recognition of this condition by dermatologists are essential for diagnosis and treatment. This review summarizes the cutaneous presentations consistent with HaT and discusses various conditions that share overlapping dermatologic symptoms with HaT.

Background on HaT

Mast cells are known to secrete several vasoactive mediators including tryptase and histamine when activated by foreign substances, similar to IgE-mediated hypersensitivity reactions. In their baseline state, mast cells continuously secrete immature forms of tryptases called protryptases.⁶ These protryptases come in 2 forms: α and β. Although mature tryptase is acutely elevatedin anaphylaxis, persistently elevated total serum tryptase levels frequently are regarded as indicative of a systemic mast cell disorder such as systemic mastocytosis (SM).³ Despite the wide-ranging phenotype of HaT, all individuals with the disorder have an elevated basal serum tryptase level (>8 ng/mL). Hereditary alpha tryptasemia has been identified as another possible cause of persistently elevated levels.^2,6

Genetics and Epidemiology of HaT—The humantryptase locus at chromosome 16p13.3 is composed of 4 paralog genes: TPSG1, TPSB2, TPSAB1, and TPSD1.⁴ Only TPSAB1 encodes for α-tryptase, while both TPSB2 and TPSAB1 encode for β-tryptase.⁴ Hereditary alpha tryptasemia is an autosomal-dominant disorder resulting from a copy number increase in the α-tryptase encoding sequence within the TPSAB1 gene. Despite the wide-ranging phenotype of HaT, all individuals identified with the disorder have a basal serum tryptase level greater than 8 ng/mL, with mean (SD) levels of 15 (5) ng/mL and 24 (6) ng/mL with gene duplication and triplication, respectively (reference range, 0–11.4 ng/mL).^2,6 Hereditary alpha tryptasemia likely is common and largely undiagnosed, with a recently estimated prevalence of 5% in the United Kingdom⁷ and 5.6% in a cohort of 125 individuals from Italy, Slovenia, and the United States.⁵

Implications of Increased α-tryptase Levels—After an inciting stimulus, the active portions of α-protryptase and β-protryptase are secreted as tetramers by activated mast cells via degranulation. In vitro, β-tryptase homotetramers have been found to play a role in anaphylaxis, while α-homotetramers are nearly inactive.^8,9 Recently, however, it has been discovered that α2β2 tetramers also can form and do so in a higher ratio in individuals with increased α-tryptase–encoding gene copies, such as those with HaT.⁸ These heterotetramers exhibit unique properties compared with the homotetramers and may stimulate epidermal growth factor–like module-containing mucinlike hormone receptor 2 and protease-activated receptor 2 (PAR2). Epidermal growth factor–like module-containing mucinlike hormone receptor 2 activation likely contributes to vibratory urticaria in patients, while activation of PAR2 may have a range of clinical effects, including worsening asthma, inflammatory bowel disease, pruritus, and the exacerbation of dermal inflammation and hyperalgesia.^8,10 Thus, α- and β-tryptase tetramers can be considered mediators that may influence the severity of disorders in which mast cells are naturally prevalent and likely contribute to the phenotype of those with HaT.⁷ Furthermore, these characteristics have been shown to potentially increase in severity with increasing tryptase levels and with increased TPSAB1 duplications.^1,2 In contrast, more than 25% of the population is deficient in α-tryptase without known deleterious effects.⁵

Cutaneous Manifestations of HaT

A case series reported by Lyons et al¹ in 2014 detailed persistent elevated basal serum tryptase levels in 9 families with an autosomal-dominant pattern of inheritance. In this cohort, 31 of 33 (94%) affected individuals had a history of atopic dermatitis (AD), and 26 of 33 (79%) affected individuals reported symptoms consistent with mast cell degranulation, including urticaria; flushing; and/or crampy abdominal pain unprovoked or triggered by heat, exercise, vibration, stress, certain foods, or minor physical stimulation.¹ A later report by Lyons et al² in 2016 identified the TPSAB1 α-tryptase–encoding sequence copy number increase as the causative entity for HaT by examining a group of 96 patients from 35 families with frequent recurrent cutaneous flushing and pruritus, sometimes associated with urticaria and sleep disruption. Flushing and pruritus were found in 45% (33/73) of those with a TPSAB1 duplication and 80% (12/15) of those with a triplication (P=.022), suggesting a gene dose effect regarding α-tryptase encoding sequence copy number and these symptoms.²

A 2019 study further explored the clinical finding of urticaria in patients with HaT by specifically examining if vibration-induced urticaria was affected by TPSAB1 gene dosage.⁸ A cohort of 56 volunteers—35 healthy and 21 with HaT—underwent tryptase genotyping and cutaneous vibratory challenge. The presence of TPSAB1 was significantly correlated with induction of vibration-induced urticaria (P<.01), as the severity and prevalence of the urticarial response increased along with α- and β-tryptase gene ratios.⁸

Urticaria and angioedema also were seen in 51% (36/70) of patients in a cohort of HaT patients in the United Kingdom, in which 41% (29/70) also had skin flushing. In contrast to prior studies, these manifestations were not more common in patients with gene triplications or quintuplications than those with duplications.⁷ In another recent retrospective evaluation conducted at Brigham and Women’s Hospital (Boston, Massachusetts)(N=101), 80% of patients aged 4 to 85 years with confirmed diagnoses of HaT had skin manifestations such as urticaria, flushing, and pruritus.⁴

HaT and Mast Cell Activation Syndrome—In 2019, a Mast Cell Disorders Committee Work Group Report outlined recommendations for diagnosing and treating primary mast cell activation syndrome (MCAS), a disorder in which mast cells seem to be more easily activated. Mast cell activation syndrome is defined as a primary clinical condition in which there are episodic signs and symptoms of systemic anaphylaxis (Table) concurrently affecting at least 2 organ systems, resulting from secreted mast cell mediators.^9,11 The 2019 report also touched on clinical criteria that lack precision for diagnosing MCAS yet are in use, including dermographism and several types of rashes.⁹ Episode triggers frequent in MCAS include hot water, alcohol, stress, exercise, infection, hormonal changes, and physical stimuli.

Hereditary alpha tryptasemia has been suggested to be a risk factor for MCAS, which also can be associated with SM and clonal MCAS.⁹ Patients with MCAS should be tested for increased α-tryptase gene copy number given the overlap in symptoms, the likely predisposition of those with HaT to develop MCAS, and the fact that these patients could be at an increased risk for anaphylaxis.^4,7,9,11 However, the clinical phenotype for HaT includes allergic disorders affecting the skin as well as neuropsychiatric and connective tissue abnormalities that are distinctive from MCAS. Although HaT may be considered a heritable risk factor for MCAS, MCAS is only 1 potential phenotype associated with HaT.⁹

Implications of HaT

Hereditary alpha tryptasemia should be considered in all patients with basal tryptase levels greater than 8 ng/mL. Cutaneous symptoms are among the most common presentations for individuals with HaT and can include AD, chronic or episodic urticaria, pruritus, flushing, and angioedema. However, HaT is unique because of the coupling of these common dermatologic findings with other abnormalities, including abdominal pain and diarrhea, hypermobile joints, and autonomic dysfunction. Patients with HaT also may manifest psychiatric concerns of anxiety, depression, and chronic pain, all of which have been linked to this disorder.

It is unclear in HaT if the presence of extra-allelic copies of tryptase in an individual is directly pathogenic. The effects of increased basal tryptase and α2β2 tetramers have been shown to likely be responsible for some of the clinical features in these individuals but also may magnify other individual underlying disease(s) or diathesis in which mast cells are naturally abundant.⁸ In the skin, this increased mast cell activation and subsequent histamine release frequently are visible as dermatographia and urticaria. However, mast cell numbers also are known to be increased in both psoriatic and AD skin lesions,¹² thus severe presentation of these diseases in conjunction with the other symptoms associated with mast cell activation should prompt suspicion for HaT.

Effects of HaT on Other Cutaneous Disease—Given the increase of mast cells in AD skin lesions and fact that 94% of patients in the 2014 Lyons et al¹ study cited a history of AD, HaT may be a risk factor in the development of AD. Interestingly, in addition to the increased mast cells in AD lesions, PAR2+ nerve fibers also are increased in AD lesions and have been implicated in the nonhistaminergic pruritus experienced by patients with AD.¹² Thus, given the proposed propensity for α2β2 tetramers to activate PAR2, it is possible this mechanism may contribute to severe pruritus in individuals with AD and concurrent HaT, as those with HaT express increased α2β2 tetramers. However, no study to date has directly compared AD symptoms in patients with concurrent HaT vs patients without it. Further research is needed on how HaT impacts other allergic and inflammatory skin diseases such as AD and psoriasis, but one may reasonably consider HaT when treating chronic inflammatory skin diseases refractory to typical interventions and/or severe presentations. Although HaT is an autosomal-dominant disorder, it is not detected by standard whole exome sequencing or microarrays. A commercial test is available, utilizing a buccal swab to test for TPSAB1 copy number.

HaT and Mast Cell Disorders—When evaluating someone with suspected HaT, it is important to screen for other symptoms of mast cell activation. For instance, in the GI tract increased mast cell activation results in activation of motor neurons and nociceptors and increases secretion and peristalsis with consequent bloating, abdominal pain, and diarrhea.¹⁰ Likewise, tryptase also has neuromodulatory effects that amplify the perception of pain and are likely responsible for the feelings of hyperalgesia reported in patients with HaT.¹³

There is substantial overlap in the clinical pictures of HaT and MCAS, and HaT is considered a heritable risk factor for MCAS. Consequently, any patient undergoing workup for MCAS also should be tested for HaT. Although HaT is associated with consistently elevated tryptase, MCAS is episodic in nature, and an increase in tryptase levels of at least 20% plus 2 ng/mL from baseline only in the presence of other symptoms reflective of mast cell activation (Table) is a prerequisite for diagnosis.⁹ Chronic signs and symptoms of atopy, chronic urticaria, and severe asthma are not indicative of MCAS but are frequently seen in HaT.

Another cause of persistently elevated tryptase levels is SM. Systemic mastocytosis is defined by aberrant clonal mast cell expansion and systemic involvement¹¹ and can cause persistent symptoms, unlike MCAS alone. However, SM also can be associated with MCAS.⁹ Notably, a baseline serum tryptase level greater than 20 ng/mL—much higher than the threshold of greater than 8 ng/mL for suspicion of HaT—is seen in 75% of SM cases and is part of the minor diagnostic criteria for the disease.^9,11 However, the 2016 study identifying increased TPSAB1 α-tryptase–encoding sequences as the causative entity for HaT by Lyons et al² found the average (SD) basal serum tryptase level in individuals with α-tryptase–encoding sequence duplications to be 15 (5) ng/mL and 24 (6) ng/mL in those with triplications. Thus, there likely is no threshold for elevated baseline tryptase levels that would indicate SM over HaT as a more likely diagnosis. However, SM will present with new persistently elevated tryptase levels, whereas the elevation in HaT is believed to be lifelong.⁵ Also in contrast to HaT, SM can present with liver, spleen, and lymph node involvement; bone sclerosis; and cytopenia.^11,14

Mastocytosis is much rarer than HaT, with an estimated prevalence of 9 cases per 100,000 individuals in the United States.¹¹ Although HaT diagnostic testing is noninvasive, SM requires a bone marrow biopsy for definitive diagnosis. Given the likely much higher prevalence of HaT than SM and the patient burden of a bone marrow biopsy, HaT should be considered before proceeding with a bone marrow biopsy to evaluate for SM when a patient presents with persistent systemic symptoms of mast cell activation and elevated baseline tryptase levels. Furthermore, it also would be prudent to test for HaT in patients with known SM, as a cohort study by Lyons et al⁵ indicated that HaT is likely more common in those with SM (12.2% [10/82] of cohort with known SM vs 5.3% of 398 controls), and patients with concurrent SM and HaT were at a higher risk for severe anaphylaxis (RR=9.5; P=.007).

Studies thus far surrounding HaT have not evaluated timing of initial symptom onset or age of initial presentation for HaT. Furthermore, there is no guarantee that those with increased TPSAB1 copy number will be symptomatic, as there have been reports of asymptomatic individuals with HaT who had basal serum levels greater than 8 ng/mL.⁷ As research into HaT continues and larger cohorts are evaluated, questions surrounding timing of symptom onset and various factors that may make someone more likely to display a particular phenotype will be answered.

Treatment—Long-term prognosis for individuals with HaT is largely unknown. Unfortunately, there are limited data to support a single effective treatment strategy for managing HaT, and treatment has varied based on predominant symptoms. For cutaneous and GI tract symptoms, trials of maximal H₁ and H₂ antihistamines twice daily have been recommended.⁴ Omalizumab was reported to improve chronic urticaria in 3 of 3 patients, showing potential promise as a treatment.⁴ Mast cell stabilizers, such as oral cromolyn, have been used for severe GI symptoms, while some patients also have reported improvement with oral ketotifen.⁶ Other medications, such as tricyclic antidepressants, clemastine fumarate, and gabapentin, have been beneficial anecdotally.⁶ Given the lack of harmful effects seen in individuals who are α-tryptase deficient, α-tryptase inhibition is an intriguing target for future therapies.

Conclusion

Patients who present with a constellation of dermatologic, allergic, GI tract, neuropsychiatric, respiratory, autonomic, and connective tissue abnormalities consistent with HaT may receive a prompt diagnosis if the association is recognized. The full relationship between HaT and other chronic dermatologic disorders is still unknown. Ultimately, heightened interest and research into HaT will lead to more treatment options available for affected patients.

Hereditary alpha tryptasemia (HaT), an autosomal-dominant disorder of tryptase overproduction, was first described in 2014 by Lyons et al.¹ It has been associated with multiple dermatologic, allergic, gastrointestinal (GI) tract, neuropsychiatric, respiratory, autonomic, and connective tissue abnormalities. These multisystem concerns may include cutaneous flushing, chronic pruritus, urticaria, GI tract symptoms, arthralgia, and autonomic dysfunction.² The diverse symptoms and the recent discovery of HaT make recognition of this disorder challenging. Currently, it also is believed that HaT is associated with an elevated risk for anaphylaxis and is a biomarker for severe symptoms in disorders with increased mast cell burden such as mastocytosis.^3-5

Given the potential cutaneous manifestations and the fact that dermatologic symptoms may be the initial presentation of HaT, awareness and recognition of this condition by dermatologists are essential for diagnosis and treatment. This review summarizes the cutaneous presentations consistent with HaT and discusses various conditions that share overlapping dermatologic symptoms with HaT.

Background on HaT

Mast cells are known to secrete several vasoactive mediators including tryptase and histamine when activated by foreign substances, similar to IgE-mediated hypersensitivity reactions. In their baseline state, mast cells continuously secrete immature forms of tryptases called protryptases.⁶ These protryptases come in 2 forms: α and β. Although mature tryptase is acutely elevatedin anaphylaxis, persistently elevated total serum tryptase levels frequently are regarded as indicative of a systemic mast cell disorder such as systemic mastocytosis (SM).³ Despite the wide-ranging phenotype of HaT, all individuals with the disorder have an elevated basal serum tryptase level (>8 ng/mL). Hereditary alpha tryptasemia has been identified as another possible cause of persistently elevated levels.^2,6

Genetics and Epidemiology of HaT—The humantryptase locus at chromosome 16p13.3 is composed of 4 paralog genes: TPSG1, TPSB2, TPSAB1, and TPSD1.⁴ Only TPSAB1 encodes for α-tryptase, while both TPSB2 and TPSAB1 encode for β-tryptase.⁴ Hereditary alpha tryptasemia is an autosomal-dominant disorder resulting from a copy number increase in the α-tryptase encoding sequence within the TPSAB1 gene. Despite the wide-ranging phenotype of HaT, all individuals identified with the disorder have a basal serum tryptase level greater than 8 ng/mL, with mean (SD) levels of 15 (5) ng/mL and 24 (6) ng/mL with gene duplication and triplication, respectively (reference range, 0–11.4 ng/mL).^2,6 Hereditary alpha tryptasemia likely is common and largely undiagnosed, with a recently estimated prevalence of 5% in the United Kingdom⁷ and 5.6% in a cohort of 125 individuals from Italy, Slovenia, and the United States.⁵

Implications of Increased α-tryptase Levels—After an inciting stimulus, the active portions of α-protryptase and β-protryptase are secreted as tetramers by activated mast cells via degranulation. In vitro, β-tryptase homotetramers have been found to play a role in anaphylaxis, while α-homotetramers are nearly inactive.^8,9 Recently, however, it has been discovered that α2β2 tetramers also can form and do so in a higher ratio in individuals with increased α-tryptase–encoding gene copies, such as those with HaT.⁸ These heterotetramers exhibit unique properties compared with the homotetramers and may stimulate epidermal growth factor–like module-containing mucinlike hormone receptor 2 and protease-activated receptor 2 (PAR2). Epidermal growth factor–like module-containing mucinlike hormone receptor 2 activation likely contributes to vibratory urticaria in patients, while activation of PAR2 may have a range of clinical effects, including worsening asthma, inflammatory bowel disease, pruritus, and the exacerbation of dermal inflammation and hyperalgesia.^8,10 Thus, α- and β-tryptase tetramers can be considered mediators that may influence the severity of disorders in which mast cells are naturally prevalent and likely contribute to the phenotype of those with HaT.⁷ Furthermore, these characteristics have been shown to potentially increase in severity with increasing tryptase levels and with increased TPSAB1 duplications.^1,2 In contrast, more than 25% of the population is deficient in α-tryptase without known deleterious effects.⁵

Cutaneous Manifestations of HaT

A case series reported by Lyons et al¹ in 2014 detailed persistent elevated basal serum tryptase levels in 9 families with an autosomal-dominant pattern of inheritance. In this cohort, 31 of 33 (94%) affected individuals had a history of atopic dermatitis (AD), and 26 of 33 (79%) affected individuals reported symptoms consistent with mast cell degranulation, including urticaria; flushing; and/or crampy abdominal pain unprovoked or triggered by heat, exercise, vibration, stress, certain foods, or minor physical stimulation.¹ A later report by Lyons et al² in 2016 identified the TPSAB1 α-tryptase–encoding sequence copy number increase as the causative entity for HaT by examining a group of 96 patients from 35 families with frequent recurrent cutaneous flushing and pruritus, sometimes associated with urticaria and sleep disruption. Flushing and pruritus were found in 45% (33/73) of those with a TPSAB1 duplication and 80% (12/15) of those with a triplication (P=.022), suggesting a gene dose effect regarding α-tryptase encoding sequence copy number and these symptoms.²

A 2019 study further explored the clinical finding of urticaria in patients with HaT by specifically examining if vibration-induced urticaria was affected by TPSAB1 gene dosage.⁸ A cohort of 56 volunteers—35 healthy and 21 with HaT—underwent tryptase genotyping and cutaneous vibratory challenge. The presence of TPSAB1 was significantly correlated with induction of vibration-induced urticaria (P<.01), as the severity and prevalence of the urticarial response increased along with α- and β-tryptase gene ratios.⁸

Urticaria and angioedema also were seen in 51% (36/70) of patients in a cohort of HaT patients in the United Kingdom, in which 41% (29/70) also had skin flushing. In contrast to prior studies, these manifestations were not more common in patients with gene triplications or quintuplications than those with duplications.⁷ In another recent retrospective evaluation conducted at Brigham and Women’s Hospital (Boston, Massachusetts)(N=101), 80% of patients aged 4 to 85 years with confirmed diagnoses of HaT had skin manifestations such as urticaria, flushing, and pruritus.⁴

HaT and Mast Cell Activation Syndrome—In 2019, a Mast Cell Disorders Committee Work Group Report outlined recommendations for diagnosing and treating primary mast cell activation syndrome (MCAS), a disorder in which mast cells seem to be more easily activated. Mast cell activation syndrome is defined as a primary clinical condition in which there are episodic signs and symptoms of systemic anaphylaxis (Table) concurrently affecting at least 2 organ systems, resulting from secreted mast cell mediators.^9,11 The 2019 report also touched on clinical criteria that lack precision for diagnosing MCAS yet are in use, including dermographism and several types of rashes.⁹ Episode triggers frequent in MCAS include hot water, alcohol, stress, exercise, infection, hormonal changes, and physical stimuli.

Hereditary alpha tryptasemia has been suggested to be a risk factor for MCAS, which also can be associated with SM and clonal MCAS.⁹ Patients with MCAS should be tested for increased α-tryptase gene copy number given the overlap in symptoms, the likely predisposition of those with HaT to develop MCAS, and the fact that these patients could be at an increased risk for anaphylaxis.^4,7,9,11 However, the clinical phenotype for HaT includes allergic disorders affecting the skin as well as neuropsychiatric and connective tissue abnormalities that are distinctive from MCAS. Although HaT may be considered a heritable risk factor for MCAS, MCAS is only 1 potential phenotype associated with HaT.⁹

Implications of HaT

Hereditary alpha tryptasemia should be considered in all patients with basal tryptase levels greater than 8 ng/mL. Cutaneous symptoms are among the most common presentations for individuals with HaT and can include AD, chronic or episodic urticaria, pruritus, flushing, and angioedema. However, HaT is unique because of the coupling of these common dermatologic findings with other abnormalities, including abdominal pain and diarrhea, hypermobile joints, and autonomic dysfunction. Patients with HaT also may manifest psychiatric concerns of anxiety, depression, and chronic pain, all of which have been linked to this disorder.

It is unclear in HaT if the presence of extra-allelic copies of tryptase in an individual is directly pathogenic. The effects of increased basal tryptase and α2β2 tetramers have been shown to likely be responsible for some of the clinical features in these individuals but also may magnify other individual underlying disease(s) or diathesis in which mast cells are naturally abundant.⁸ In the skin, this increased mast cell activation and subsequent histamine release frequently are visible as dermatographia and urticaria. However, mast cell numbers also are known to be increased in both psoriatic and AD skin lesions,¹² thus severe presentation of these diseases in conjunction with the other symptoms associated with mast cell activation should prompt suspicion for HaT.

Effects of HaT on Other Cutaneous Disease—Given the increase of mast cells in AD skin lesions and fact that 94% of patients in the 2014 Lyons et al¹ study cited a history of AD, HaT may be a risk factor in the development of AD. Interestingly, in addition to the increased mast cells in AD lesions, PAR2+ nerve fibers also are increased in AD lesions and have been implicated in the nonhistaminergic pruritus experienced by patients with AD.¹² Thus, given the proposed propensity for α2β2 tetramers to activate PAR2, it is possible this mechanism may contribute to severe pruritus in individuals with AD and concurrent HaT, as those with HaT express increased α2β2 tetramers. However, no study to date has directly compared AD symptoms in patients with concurrent HaT vs patients without it. Further research is needed on how HaT impacts other allergic and inflammatory skin diseases such as AD and psoriasis, but one may reasonably consider HaT when treating chronic inflammatory skin diseases refractory to typical interventions and/or severe presentations. Although HaT is an autosomal-dominant disorder, it is not detected by standard whole exome sequencing or microarrays. A commercial test is available, utilizing a buccal swab to test for TPSAB1 copy number.

HaT and Mast Cell Disorders—When evaluating someone with suspected HaT, it is important to screen for other symptoms of mast cell activation. For instance, in the GI tract increased mast cell activation results in activation of motor neurons and nociceptors and increases secretion and peristalsis with consequent bloating, abdominal pain, and diarrhea.¹⁰ Likewise, tryptase also has neuromodulatory effects that amplify the perception of pain and are likely responsible for the feelings of hyperalgesia reported in patients with HaT.¹³

There is substantial overlap in the clinical pictures of HaT and MCAS, and HaT is considered a heritable risk factor for MCAS. Consequently, any patient undergoing workup for MCAS also should be tested for HaT. Although HaT is associated with consistently elevated tryptase, MCAS is episodic in nature, and an increase in tryptase levels of at least 20% plus 2 ng/mL from baseline only in the presence of other symptoms reflective of mast cell activation (Table) is a prerequisite for diagnosis.⁹ Chronic signs and symptoms of atopy, chronic urticaria, and severe asthma are not indicative of MCAS but are frequently seen in HaT.

Another cause of persistently elevated tryptase levels is SM. Systemic mastocytosis is defined by aberrant clonal mast cell expansion and systemic involvement¹¹ and can cause persistent symptoms, unlike MCAS alone. However, SM also can be associated with MCAS.⁹ Notably, a baseline serum tryptase level greater than 20 ng/mL—much higher than the threshold of greater than 8 ng/mL for suspicion of HaT—is seen in 75% of SM cases and is part of the minor diagnostic criteria for the disease.^9,11 However, the 2016 study identifying increased TPSAB1 α-tryptase–encoding sequences as the causative entity for HaT by Lyons et al² found the average (SD) basal serum tryptase level in individuals with α-tryptase–encoding sequence duplications to be 15 (5) ng/mL and 24 (6) ng/mL in those with triplications. Thus, there likely is no threshold for elevated baseline tryptase levels that would indicate SM over HaT as a more likely diagnosis. However, SM will present with new persistently elevated tryptase levels, whereas the elevation in HaT is believed to be lifelong.⁵ Also in contrast to HaT, SM can present with liver, spleen, and lymph node involvement; bone sclerosis; and cytopenia.^11,14

Mastocytosis is much rarer than HaT, with an estimated prevalence of 9 cases per 100,000 individuals in the United States.¹¹ Although HaT diagnostic testing is noninvasive, SM requires a bone marrow biopsy for definitive diagnosis. Given the likely much higher prevalence of HaT than SM and the patient burden of a bone marrow biopsy, HaT should be considered before proceeding with a bone marrow biopsy to evaluate for SM when a patient presents with persistent systemic symptoms of mast cell activation and elevated baseline tryptase levels. Furthermore, it also would be prudent to test for HaT in patients with known SM, as a cohort study by Lyons et al⁵ indicated that HaT is likely more common in those with SM (12.2% [10/82] of cohort with known SM vs 5.3% of 398 controls), and patients with concurrent SM and HaT were at a higher risk for severe anaphylaxis (RR=9.5; P=.007).

Studies thus far surrounding HaT have not evaluated timing of initial symptom onset or age of initial presentation for HaT. Furthermore, there is no guarantee that those with increased TPSAB1 copy number will be symptomatic, as there have been reports of asymptomatic individuals with HaT who had basal serum levels greater than 8 ng/mL.⁷ As research into HaT continues and larger cohorts are evaluated, questions surrounding timing of symptom onset and various factors that may make someone more likely to display a particular phenotype will be answered.

Treatment—Long-term prognosis for individuals with HaT is largely unknown. Unfortunately, there are limited data to support a single effective treatment strategy for managing HaT, and treatment has varied based on predominant symptoms. For cutaneous and GI tract symptoms, trials of maximal H₁ and H₂ antihistamines twice daily have been recommended.⁴ Omalizumab was reported to improve chronic urticaria in 3 of 3 patients, showing potential promise as a treatment.⁴ Mast cell stabilizers, such as oral cromolyn, have been used for severe GI symptoms, while some patients also have reported improvement with oral ketotifen.⁶ Other medications, such as tricyclic antidepressants, clemastine fumarate, and gabapentin, have been beneficial anecdotally.⁶ Given the lack of harmful effects seen in individuals who are α-tryptase deficient, α-tryptase inhibition is an intriguing target for future therapies.

Conclusion

Patients who present with a constellation of dermatologic, allergic, GI tract, neuropsychiatric, respiratory, autonomic, and connective tissue abnormalities consistent with HaT may receive a prompt diagnosis if the association is recognized. The full relationship between HaT and other chronic dermatologic disorders is still unknown. Ultimately, heightened interest and research into HaT will lead to more treatment options available for affected patients.

Hereditary alpha tryptasemia (HaT), an autosomal-dominant disorder of tryptase overproduction, was first described in 2014 by Lyons et al.¹ It has been associated with multiple dermatologic, allergic, gastrointestinal (GI) tract, neuropsychiatric, respiratory, autonomic, and connective tissue abnormalities. These multisystem concerns may include cutaneous flushing, chronic pruritus, urticaria, GI tract symptoms, arthralgia, and autonomic dysfunction.² The diverse symptoms and the recent discovery of HaT make recognition of this disorder challenging. Currently, it also is believed that HaT is associated with an elevated risk for anaphylaxis and is a biomarker for severe symptoms in disorders with increased mast cell burden such as mastocytosis.^3-5

Given the potential cutaneous manifestations and the fact that dermatologic symptoms may be the initial presentation of HaT, awareness and recognition of this condition by dermatologists are essential for diagnosis and treatment. This review summarizes the cutaneous presentations consistent with HaT and discusses various conditions that share overlapping dermatologic symptoms with HaT.

Background on HaT

Mast cells are known to secrete several vasoactive mediators including tryptase and histamine when activated by foreign substances, similar to IgE-mediated hypersensitivity reactions. In their baseline state, mast cells continuously secrete immature forms of tryptases called protryptases.⁶ These protryptases come in 2 forms: α and β. Although mature tryptase is acutely elevatedin anaphylaxis, persistently elevated total serum tryptase levels frequently are regarded as indicative of a systemic mast cell disorder such as systemic mastocytosis (SM).³ Despite the wide-ranging phenotype of HaT, all individuals with the disorder have an elevated basal serum tryptase level (>8 ng/mL). Hereditary alpha tryptasemia has been identified as another possible cause of persistently elevated levels.^2,6

Genetics and Epidemiology of HaT—The humantryptase locus at chromosome 16p13.3 is composed of 4 paralog genes: TPSG1, TPSB2, TPSAB1, and TPSD1.⁴ Only TPSAB1 encodes for α-tryptase, while both TPSB2 and TPSAB1 encode for β-tryptase.⁴ Hereditary alpha tryptasemia is an autosomal-dominant disorder resulting from a copy number increase in the α-tryptase encoding sequence within the TPSAB1 gene. Despite the wide-ranging phenotype of HaT, all individuals identified with the disorder have a basal serum tryptase level greater than 8 ng/mL, with mean (SD) levels of 15 (5) ng/mL and 24 (6) ng/mL with gene duplication and triplication, respectively (reference range, 0–11.4 ng/mL).^2,6 Hereditary alpha tryptasemia likely is common and largely undiagnosed, with a recently estimated prevalence of 5% in the United Kingdom⁷ and 5.6% in a cohort of 125 individuals from Italy, Slovenia, and the United States.⁵

Implications of Increased α-tryptase Levels—After an inciting stimulus, the active portions of α-protryptase and β-protryptase are secreted as tetramers by activated mast cells via degranulation. In vitro, β-tryptase homotetramers have been found to play a role in anaphylaxis, while α-homotetramers are nearly inactive.^8,9 Recently, however, it has been discovered that α2β2 tetramers also can form and do so in a higher ratio in individuals with increased α-tryptase–encoding gene copies, such as those with HaT.⁸ These heterotetramers exhibit unique properties compared with the homotetramers and may stimulate epidermal growth factor–like module-containing mucinlike hormone receptor 2 and protease-activated receptor 2 (PAR2). Epidermal growth factor–like module-containing mucinlike hormone receptor 2 activation likely contributes to vibratory urticaria in patients, while activation of PAR2 may have a range of clinical effects, including worsening asthma, inflammatory bowel disease, pruritus, and the exacerbation of dermal inflammation and hyperalgesia.^8,10 Thus, α- and β-tryptase tetramers can be considered mediators that may influence the severity of disorders in which mast cells are naturally prevalent and likely contribute to the phenotype of those with HaT.⁷ Furthermore, these characteristics have been shown to potentially increase in severity with increasing tryptase levels and with increased TPSAB1 duplications.^1,2 In contrast, more than 25% of the population is deficient in α-tryptase without known deleterious effects.⁵

Cutaneous Manifestations of HaT

A case series reported by Lyons et al¹ in 2014 detailed persistent elevated basal serum tryptase levels in 9 families with an autosomal-dominant pattern of inheritance. In this cohort, 31 of 33 (94%) affected individuals had a history of atopic dermatitis (AD), and 26 of 33 (79%) affected individuals reported symptoms consistent with mast cell degranulation, including urticaria; flushing; and/or crampy abdominal pain unprovoked or triggered by heat, exercise, vibration, stress, certain foods, or minor physical stimulation.¹ A later report by Lyons et al² in 2016 identified the TPSAB1 α-tryptase–encoding sequence copy number increase as the causative entity for HaT by examining a group of 96 patients from 35 families with frequent recurrent cutaneous flushing and pruritus, sometimes associated with urticaria and sleep disruption. Flushing and pruritus were found in 45% (33/73) of those with a TPSAB1 duplication and 80% (12/15) of those with a triplication (P=.022), suggesting a gene dose effect regarding α-tryptase encoding sequence copy number and these symptoms.²

A 2019 study further explored the clinical finding of urticaria in patients with HaT by specifically examining if vibration-induced urticaria was affected by TPSAB1 gene dosage.⁸ A cohort of 56 volunteers—35 healthy and 21 with HaT—underwent tryptase genotyping and cutaneous vibratory challenge. The presence of TPSAB1 was significantly correlated with induction of vibration-induced urticaria (P<.01), as the severity and prevalence of the urticarial response increased along with α- and β-tryptase gene ratios.⁸

Urticaria and angioedema also were seen in 51% (36/70) of patients in a cohort of HaT patients in the United Kingdom, in which 41% (29/70) also had skin flushing. In contrast to prior studies, these manifestations were not more common in patients with gene triplications or quintuplications than those with duplications.⁷ In another recent retrospective evaluation conducted at Brigham and Women’s Hospital (Boston, Massachusetts)(N=101), 80% of patients aged 4 to 85 years with confirmed diagnoses of HaT had skin manifestations such as urticaria, flushing, and pruritus.⁴

HaT and Mast Cell Activation Syndrome—In 2019, a Mast Cell Disorders Committee Work Group Report outlined recommendations for diagnosing and treating primary mast cell activation syndrome (MCAS), a disorder in which mast cells seem to be more easily activated. Mast cell activation syndrome is defined as a primary clinical condition in which there are episodic signs and symptoms of systemic anaphylaxis (Table) concurrently affecting at least 2 organ systems, resulting from secreted mast cell mediators.^9,11 The 2019 report also touched on clinical criteria that lack precision for diagnosing MCAS yet are in use, including dermographism and several types of rashes.⁹ Episode triggers frequent in MCAS include hot water, alcohol, stress, exercise, infection, hormonal changes, and physical stimuli.

Hereditary alpha tryptasemia has been suggested to be a risk factor for MCAS, which also can be associated with SM and clonal MCAS.⁹ Patients with MCAS should be tested for increased α-tryptase gene copy number given the overlap in symptoms, the likely predisposition of those with HaT to develop MCAS, and the fact that these patients could be at an increased risk for anaphylaxis.^4,7,9,11 However, the clinical phenotype for HaT includes allergic disorders affecting the skin as well as neuropsychiatric and connective tissue abnormalities that are distinctive from MCAS. Although HaT may be considered a heritable risk factor for MCAS, MCAS is only 1 potential phenotype associated with HaT.⁹

Implications of HaT

Hereditary alpha tryptasemia should be considered in all patients with basal tryptase levels greater than 8 ng/mL. Cutaneous symptoms are among the most common presentations for individuals with HaT and can include AD, chronic or episodic urticaria, pruritus, flushing, and angioedema. However, HaT is unique because of the coupling of these common dermatologic findings with other abnormalities, including abdominal pain and diarrhea, hypermobile joints, and autonomic dysfunction. Patients with HaT also may manifest psychiatric concerns of anxiety, depression, and chronic pain, all of which have been linked to this disorder.

It is unclear in HaT if the presence of extra-allelic copies of tryptase in an individual is directly pathogenic. The effects of increased basal tryptase and α2β2 tetramers have been shown to likely be responsible for some of the clinical features in these individuals but also may magnify other individual underlying disease(s) or diathesis in which mast cells are naturally abundant.⁸ In the skin, this increased mast cell activation and subsequent histamine release frequently are visible as dermatographia and urticaria. However, mast cell numbers also are known to be increased in both psoriatic and AD skin lesions,¹² thus severe presentation of these diseases in conjunction with the other symptoms associated with mast cell activation should prompt suspicion for HaT.

Effects of HaT on Other Cutaneous Disease—Given the increase of mast cells in AD skin lesions and fact that 94% of patients in the 2014 Lyons et al¹ study cited a history of AD, HaT may be a risk factor in the development of AD. Interestingly, in addition to the increased mast cells in AD lesions, PAR2+ nerve fibers also are increased in AD lesions and have been implicated in the nonhistaminergic pruritus experienced by patients with AD.¹² Thus, given the proposed propensity for α2β2 tetramers to activate PAR2, it is possible this mechanism may contribute to severe pruritus in individuals with AD and concurrent HaT, as those with HaT express increased α2β2 tetramers. However, no study to date has directly compared AD symptoms in patients with concurrent HaT vs patients without it. Further research is needed on how HaT impacts other allergic and inflammatory skin diseases such as AD and psoriasis, but one may reasonably consider HaT when treating chronic inflammatory skin diseases refractory to typical interventions and/or severe presentations. Although HaT is an autosomal-dominant disorder, it is not detected by standard whole exome sequencing or microarrays. A commercial test is available, utilizing a buccal swab to test for TPSAB1 copy number.

HaT and Mast Cell Disorders—When evaluating someone with suspected HaT, it is important to screen for other symptoms of mast cell activation. For instance, in the GI tract increased mast cell activation results in activation of motor neurons and nociceptors and increases secretion and peristalsis with consequent bloating, abdominal pain, and diarrhea.¹⁰ Likewise, tryptase also has neuromodulatory effects that amplify the perception of pain and are likely responsible for the feelings of hyperalgesia reported in patients with HaT.¹³

There is substantial overlap in the clinical pictures of HaT and MCAS, and HaT is considered a heritable risk factor for MCAS. Consequently, any patient undergoing workup for MCAS also should be tested for HaT. Although HaT is associated with consistently elevated tryptase, MCAS is episodic in nature, and an increase in tryptase levels of at least 20% plus 2 ng/mL from baseline only in the presence of other symptoms reflective of mast cell activation (Table) is a prerequisite for diagnosis.⁹ Chronic signs and symptoms of atopy, chronic urticaria, and severe asthma are not indicative of MCAS but are frequently seen in HaT.

Another cause of persistently elevated tryptase levels is SM. Systemic mastocytosis is defined by aberrant clonal mast cell expansion and systemic involvement¹¹ and can cause persistent symptoms, unlike MCAS alone. However, SM also can be associated with MCAS.⁹ Notably, a baseline serum tryptase level greater than 20 ng/mL—much higher than the threshold of greater than 8 ng/mL for suspicion of HaT—is seen in 75% of SM cases and is part of the minor diagnostic criteria for the disease.^9,11 However, the 2016 study identifying increased TPSAB1 α-tryptase–encoding sequences as the causative entity for HaT by Lyons et al² found the average (SD) basal serum tryptase level in individuals with α-tryptase–encoding sequence duplications to be 15 (5) ng/mL and 24 (6) ng/mL in those with triplications. Thus, there likely is no threshold for elevated baseline tryptase levels that would indicate SM over HaT as a more likely diagnosis. However, SM will present with new persistently elevated tryptase levels, whereas the elevation in HaT is believed to be lifelong.⁵ Also in contrast to HaT, SM can present with liver, spleen, and lymph node involvement; bone sclerosis; and cytopenia.^11,14

Mastocytosis is much rarer than HaT, with an estimated prevalence of 9 cases per 100,000 individuals in the United States.¹¹ Although HaT diagnostic testing is noninvasive, SM requires a bone marrow biopsy for definitive diagnosis. Given the likely much higher prevalence of HaT than SM and the patient burden of a bone marrow biopsy, HaT should be considered before proceeding with a bone marrow biopsy to evaluate for SM when a patient presents with persistent systemic symptoms of mast cell activation and elevated baseline tryptase levels. Furthermore, it also would be prudent to test for HaT in patients with known SM, as a cohort study by Lyons et al⁵ indicated that HaT is likely more common in those with SM (12.2% [10/82] of cohort with known SM vs 5.3% of 398 controls), and patients with concurrent SM and HaT were at a higher risk for severe anaphylaxis (RR=9.5; P=.007).

Studies thus far surrounding HaT have not evaluated timing of initial symptom onset or age of initial presentation for HaT. Furthermore, there is no guarantee that those with increased TPSAB1 copy number will be symptomatic, as there have been reports of asymptomatic individuals with HaT who had basal serum levels greater than 8 ng/mL.⁷ As research into HaT continues and larger cohorts are evaluated, questions surrounding timing of symptom onset and various factors that may make someone more likely to display a particular phenotype will be answered.

Treatment—Long-term prognosis for individuals with HaT is largely unknown. Unfortunately, there are limited data to support a single effective treatment strategy for managing HaT, and treatment has varied based on predominant symptoms. For cutaneous and GI tract symptoms, trials of maximal H₁ and H₂ antihistamines twice daily have been recommended.⁴ Omalizumab was reported to improve chronic urticaria in 3 of 3 patients, showing potential promise as a treatment.⁴ Mast cell stabilizers, such as oral cromolyn, have been used for severe GI symptoms, while some patients also have reported improvement with oral ketotifen.⁶ Other medications, such as tricyclic antidepressants, clemastine fumarate, and gabapentin, have been beneficial anecdotally.⁶ Given the lack of harmful effects seen in individuals who are α-tryptase deficient, α-tryptase inhibition is an intriguing target for future therapies.

Conclusion

Patients who present with a constellation of dermatologic, allergic, GI tract, neuropsychiatric, respiratory, autonomic, and connective tissue abnormalities consistent with HaT may receive a prompt diagnosis if the association is recognized. The full relationship between HaT and other chronic dermatologic disorders is still unknown. Ultimately, heightened interest and research into HaT will lead to more treatment options available for affected patients.

Contact dermatitis is a common problem in the floral bulb industry and is considered an occupational disease. Daffodils (Narcissus species)(Figure) are thought to be the most common cause of irritant contact dermatitis among florists.¹

Clinical Importance

Picking daffodils can start as early as October, when the flowers are still closed. The picker’s hand slides down the stem to snap the stalk at the base. This potentially traumatic maneuver to the web of the fingers leads to abrasions, which are irritated by the sap and cause granulomatous sores and paronychia. An experienced picker can pick 20,000 flowers a day, leading to extensive contact with sap.²

Eczematous or granulomatous rash on the arms also is seen as the sap irritates the wrist and forearm. The pickers often hold the flowers until a bunch of 10 has been collected. The 10 flowers are held together by a rubber band and stacked along the arm, the chin, and the axilla, causing the rash to extend to those areas. Sap also can be transferred by the hand to other parts of the body, such as the face. In men, sap can be transferred to the genitalia as the men urinate in the field.

Narcissus also can cause poisoning if ingested by humans or animals. Researchers who analyzed calls made to the New Zealand Natural Poisons Centre between 2003 and 2010 determined that daffodil was the 11th most common call for plant-related poisoning.³

Although the severity of plant poisoning often is low due to the small amount of plant material usually consumed, more severe poisoning can occur when the plant is eaten for medicinal purposes or mistaken for an edible plant.³ Vomiting, respiratory symptoms, abdominal pain, diarrhea, trembling, and convulsions can occur when daffodils are ingested. Death has been reported due to ingestion of the bulbs.⁴

In February 2010, 10 children aged 10 and 11 years and their 22-year-old guide presented to an emergency department in Israel after ingesting Narcissus bulbs, which were mistakenly believed to be the bulbs of onions.⁴ Eight children and the guide vomited. One child and the guide reported abdominal pain. All were discharged in stable condition after 4 hours of observation.⁴

Clinical Manifestations

Daffodil rash or lily rash was first described in 1910.⁵ The typical rash presents as dryness, fissures, scaling, and erythema of the fingertips, hands, and forearms, often with subungual hyperkeratosis. Vesicles and pustules may be seen. The rash may extend to other areas of the body, including the face.⁶

Use of protective gloves and clothing to avoid contact with the plant is recommended.² Treatment includes stopping contact with the irritant, eye irrigation, and supportive measures (airway, breathing, and circulation). Activated charcoal can be helpful if used within 1 hour after ingestion but is contraindicated in vomiting patients.⁴

Identifying Features

The genus Narcissus is in the family Amaryllidaceae and contains ornamental plants, including daffodil (trumpet Narcissus, Narcissus pseudonarcissus), jonquil (Narcissus jonquilla), and poet’s narcissus (Narcissus poeticus). Most species are perennial; the plant emerges from a bulb in spring. Leaves originate from the base of the plant and range from 5-cm to 1.2-meters long, depending on the species. The flowers span a range of shapes and colors—from a trumpet (the daffodil) to a ringlike cup (poet’s Narcissus) and in yellow, white, and pink.⁷

Distribution and Plant Facts

Distribution—There are approximately 80 to 100 wild Narcissus species, which are found in southwestern Europe, North Africa, the Balkan Peninsula, Italy, and France. There are more than 27,000 Narcissus cultivars registered in the International Daffodil Register.⁸

Plant Facts—The daffodil is the national flower of Wales. It also is often used to depict hope and joy and is the symbol of cancer charities in many countries.⁹

The name Narcissus is believed to have originated from Greek mythology. A handsome youth, Narcissus, fell in love with his own reflection, for which the gods punished him by turning him into a flower.¹⁰

Another theory states that Narcissus is derived from the Greek word narkao (to benumb) due to its narcotic properties. When an open wound is subjected to an extract of the bulb, numbness of the entire nervous system is said to occur as well as paralysis of the heart. This narcotic effect led Socrates to refer to the Narcissus plant as the “chaplet of the infernal gods.”¹¹

Narcissus is an important flower in various ethnic rituals. The Greeks often planted daffodils near tombs. In Muslim culture, white is believed to be the symbol of good and purity; Narcissus was one of the most common white-flowered plants found in Muslim graveyards.¹²

Medicinal Qualities and Uses—Narcissus species have been used as medicinal plants for a variety of ailments. For example, Narcissus tazetta contains flavonoids, alkaloids, saponins, tannins, cardiac glycosides, oil, steroids, terpenoids, and anthraquinones that contribute to its antibacterial, antifungal, antiviral, antimalarial, anticancer, antioxidant, dermatologic, cardiovascular, immunomodulatory, and acetylcholinesterase inhibitory effects.¹³ In a study, chloroform extracts from N tazetta bulbs were found to be more active than doxorubicin against hepatocellular and colon cancer cell lines.¹⁴

More than 500 alkaloids have been isolated from the Narcissus genus.¹⁵ In 2001, the US Food and Drug Administration approved one of the alkaloids, galantamine, for the treatment of mild to moderate stages of Alzheimer disease.¹⁶ Galantamine selectively and reversibly inhibits acetylcholinesterase, the enzyme believed responsible for neurodegeneration seen in Alzheimer disease. Plants are the main source of galantamine, despite the ability of pharmaceutical companies to synthesize the compound. Galantamine hydrobromide is sold by prescription (Razadyne [Janssen Pharmaceuticals, Inc]); generic formulations approved by the US Food and Drug Administration have been produced by more than 15 pharmaceutical companies.^17,18

Irritant and Allergen

Sap found in the bulbs and hollow stems of Narcissus contains calcium oxalate crystals, or raphides. The minute, needle-shaped calcium oxalate crystals are believed to be a waste product of cellular metabolism.¹⁹ When the plant structure is compromised by pickers snapping the stalk, the sharp crystals penetrate the skin to cause an irritant contact dermatitis.

Relevant Research—A study used electron microscopy to characterize the structure of raphides from various plants,² though not from Narcissus species; the structure of each raphide was then compared to the degree of irritation it produced. The researchers concluded that more elongated crystals (those containing barbs) produce a greater degree of irritation. Narcissus species are known to cause varying degrees of skin irritation: For example, N tazetta rarely causes skin irritation, whereas N pseudonarcissi (daffodil) tends to cause remarkably more skin irritation.²

Allergic reactions to and strong toxicity from Narcissus species are not well understood. In a study, only 2 alkaloids—homolycorine and masonin—produced a weakly positive reaction in patch tests on sensitized guinea pigs, which correlates with the finding of a different study, in which only 2 of 12 patients whose findings were examined over 14 years had a positive patch test for Narcissus.^20,21

However, IgE-mediated allergies indicative of an allergic response to Narcissus have been reported. A study isolated an allergenic protein, narcin, from bulbs of N tazetta. Narcin is a 13-kDa protein with potent allergenic effects capable of inducing production of proinflammatory cytokines and increasing IgE levels in mononuclear cells in peripheral blood.²²

More research is required to find and understand the compounds responsible for causing an allergic reaction to Narcissus.

Contact dermatitis is a common problem in the floral bulb industry and is considered an occupational disease. Daffodils (Narcissus species)(Figure) are thought to be the most common cause of irritant contact dermatitis among florists.¹

Clinical Importance

Picking daffodils can start as early as October, when the flowers are still closed. The picker’s hand slides down the stem to snap the stalk at the base. This potentially traumatic maneuver to the web of the fingers leads to abrasions, which are irritated by the sap and cause granulomatous sores and paronychia. An experienced picker can pick 20,000 flowers a day, leading to extensive contact with sap.²

Eczematous or granulomatous rash on the arms also is seen as the sap irritates the wrist and forearm. The pickers often hold the flowers until a bunch of 10 has been collected. The 10 flowers are held together by a rubber band and stacked along the arm, the chin, and the axilla, causing the rash to extend to those areas. Sap also can be transferred by the hand to other parts of the body, such as the face. In men, sap can be transferred to the genitalia as the men urinate in the field.

Narcissus also can cause poisoning if ingested by humans or animals. Researchers who analyzed calls made to the New Zealand Natural Poisons Centre between 2003 and 2010 determined that daffodil was the 11th most common call for plant-related poisoning.³

Although the severity of plant poisoning often is low due to the small amount of plant material usually consumed, more severe poisoning can occur when the plant is eaten for medicinal purposes or mistaken for an edible plant.³ Vomiting, respiratory symptoms, abdominal pain, diarrhea, trembling, and convulsions can occur when daffodils are ingested. Death has been reported due to ingestion of the bulbs.⁴

In February 2010, 10 children aged 10 and 11 years and their 22-year-old guide presented to an emergency department in Israel after ingesting Narcissus bulbs, which were mistakenly believed to be the bulbs of onions.⁴ Eight children and the guide vomited. One child and the guide reported abdominal pain. All were discharged in stable condition after 4 hours of observation.⁴

Clinical Manifestations

Daffodil rash or lily rash was first described in 1910.⁵ The typical rash presents as dryness, fissures, scaling, and erythema of the fingertips, hands, and forearms, often with subungual hyperkeratosis. Vesicles and pustules may be seen. The rash may extend to other areas of the body, including the face.⁶

Use of protective gloves and clothing to avoid contact with the plant is recommended.² Treatment includes stopping contact with the irritant, eye irrigation, and supportive measures (airway, breathing, and circulation). Activated charcoal can be helpful if used within 1 hour after ingestion but is contraindicated in vomiting patients.⁴

Identifying Features

The genus Narcissus is in the family Amaryllidaceae and contains ornamental plants, including daffodil (trumpet Narcissus, Narcissus pseudonarcissus), jonquil (Narcissus jonquilla), and poet’s narcissus (Narcissus poeticus). Most species are perennial; the plant emerges from a bulb in spring. Leaves originate from the base of the plant and range from 5-cm to 1.2-meters long, depending on the species. The flowers span a range of shapes and colors—from a trumpet (the daffodil) to a ringlike cup (poet’s Narcissus) and in yellow, white, and pink.⁷

Distribution and Plant Facts

Distribution—There are approximately 80 to 100 wild Narcissus species, which are found in southwestern Europe, North Africa, the Balkan Peninsula, Italy, and France. There are more than 27,000 Narcissus cultivars registered in the International Daffodil Register.⁸

Plant Facts—The daffodil is the national flower of Wales. It also is often used to depict hope and joy and is the symbol of cancer charities in many countries.⁹

The name Narcissus is believed to have originated from Greek mythology. A handsome youth, Narcissus, fell in love with his own reflection, for which the gods punished him by turning him into a flower.¹⁰

Another theory states that Narcissus is derived from the Greek word narkao (to benumb) due to its narcotic properties. When an open wound is subjected to an extract of the bulb, numbness of the entire nervous system is said to occur as well as paralysis of the heart. This narcotic effect led Socrates to refer to the Narcissus plant as the “chaplet of the infernal gods.”¹¹

Narcissus is an important flower in various ethnic rituals. The Greeks often planted daffodils near tombs. In Muslim culture, white is believed to be the symbol of good and purity; Narcissus was one of the most common white-flowered plants found in Muslim graveyards.¹²

Medicinal Qualities and Uses—Narcissus species have been used as medicinal plants for a variety of ailments. For example, Narcissus tazetta contains flavonoids, alkaloids, saponins, tannins, cardiac glycosides, oil, steroids, terpenoids, and anthraquinones that contribute to its antibacterial, antifungal, antiviral, antimalarial, anticancer, antioxidant, dermatologic, cardiovascular, immunomodulatory, and acetylcholinesterase inhibitory effects.¹³ In a study, chloroform extracts from N tazetta bulbs were found to be more active than doxorubicin against hepatocellular and colon cancer cell lines.¹⁴

More than 500 alkaloids have been isolated from the Narcissus genus.¹⁵ In 2001, the US Food and Drug Administration approved one of the alkaloids, galantamine, for the treatment of mild to moderate stages of Alzheimer disease.¹⁶ Galantamine selectively and reversibly inhibits acetylcholinesterase, the enzyme believed responsible for neurodegeneration seen in Alzheimer disease. Plants are the main source of galantamine, despite the ability of pharmaceutical companies to synthesize the compound. Galantamine hydrobromide is sold by prescription (Razadyne [Janssen Pharmaceuticals, Inc]); generic formulations approved by the US Food and Drug Administration have been produced by more than 15 pharmaceutical companies.^17,18

Irritant and Allergen

Sap found in the bulbs and hollow stems of Narcissus contains calcium oxalate crystals, or raphides. The minute, needle-shaped calcium oxalate crystals are believed to be a waste product of cellular metabolism.¹⁹ When the plant structure is compromised by pickers snapping the stalk, the sharp crystals penetrate the skin to cause an irritant contact dermatitis.

Relevant Research—A study used electron microscopy to characterize the structure of raphides from various plants,² though not from Narcissus species; the structure of each raphide was then compared to the degree of irritation it produced. The researchers concluded that more elongated crystals (those containing barbs) produce a greater degree of irritation. Narcissus species are known to cause varying degrees of skin irritation: For example, N tazetta rarely causes skin irritation, whereas N pseudonarcissi (daffodil) tends to cause remarkably more skin irritation.²

Allergic reactions to and strong toxicity from Narcissus species are not well understood. In a study, only 2 alkaloids—homolycorine and masonin—produced a weakly positive reaction in patch tests on sensitized guinea pigs, which correlates with the finding of a different study, in which only 2 of 12 patients whose findings were examined over 14 years had a positive patch test for Narcissus.^20,21

However, IgE-mediated allergies indicative of an allergic response to Narcissus have been reported. A study isolated an allergenic protein, narcin, from bulbs of N tazetta. Narcin is a 13-kDa protein with potent allergenic effects capable of inducing production of proinflammatory cytokines and increasing IgE levels in mononuclear cells in peripheral blood.²²

More research is required to find and understand the compounds responsible for causing an allergic reaction to Narcissus.

Contact dermatitis is a common problem in the floral bulb industry and is considered an occupational disease. Daffodils (Narcissus species)(Figure) are thought to be the most common cause of irritant contact dermatitis among florists.¹

Clinical Importance

Picking daffodils can start as early as October, when the flowers are still closed. The picker’s hand slides down the stem to snap the stalk at the base. This potentially traumatic maneuver to the web of the fingers leads to abrasions, which are irritated by the sap and cause granulomatous sores and paronychia. An experienced picker can pick 20,000 flowers a day, leading to extensive contact with sap.²

Eczematous or granulomatous rash on the arms also is seen as the sap irritates the wrist and forearm. The pickers often hold the flowers until a bunch of 10 has been collected. The 10 flowers are held together by a rubber band and stacked along the arm, the chin, and the axilla, causing the rash to extend to those areas. Sap also can be transferred by the hand to other parts of the body, such as the face. In men, sap can be transferred to the genitalia as the men urinate in the field.

Narcissus also can cause poisoning if ingested by humans or animals. Researchers who analyzed calls made to the New Zealand Natural Poisons Centre between 2003 and 2010 determined that daffodil was the 11th most common call for plant-related poisoning.³

Although the severity of plant poisoning often is low due to the small amount of plant material usually consumed, more severe poisoning can occur when the plant is eaten for medicinal purposes or mistaken for an edible plant.³ Vomiting, respiratory symptoms, abdominal pain, diarrhea, trembling, and convulsions can occur when daffodils are ingested. Death has been reported due to ingestion of the bulbs.⁴

In February 2010, 10 children aged 10 and 11 years and their 22-year-old guide presented to an emergency department in Israel after ingesting Narcissus bulbs, which were mistakenly believed to be the bulbs of onions.⁴ Eight children and the guide vomited. One child and the guide reported abdominal pain. All were discharged in stable condition after 4 hours of observation.⁴

Clinical Manifestations

Daffodil rash or lily rash was first described in 1910.⁵ The typical rash presents as dryness, fissures, scaling, and erythema of the fingertips, hands, and forearms, often with subungual hyperkeratosis. Vesicles and pustules may be seen. The rash may extend to other areas of the body, including the face.⁶

Use of protective gloves and clothing to avoid contact with the plant is recommended.² Treatment includes stopping contact with the irritant, eye irrigation, and supportive measures (airway, breathing, and circulation). Activated charcoal can be helpful if used within 1 hour after ingestion but is contraindicated in vomiting patients.⁴

Identifying Features

The genus Narcissus is in the family Amaryllidaceae and contains ornamental plants, including daffodil (trumpet Narcissus, Narcissus pseudonarcissus), jonquil (Narcissus jonquilla), and poet’s narcissus (Narcissus poeticus). Most species are perennial; the plant emerges from a bulb in spring. Leaves originate from the base of the plant and range from 5-cm to 1.2-meters long, depending on the species. The flowers span a range of shapes and colors—from a trumpet (the daffodil) to a ringlike cup (poet’s Narcissus) and in yellow, white, and pink.⁷

Distribution and Plant Facts

Distribution—There are approximately 80 to 100 wild Narcissus species, which are found in southwestern Europe, North Africa, the Balkan Peninsula, Italy, and France. There are more than 27,000 Narcissus cultivars registered in the International Daffodil Register.⁸

Plant Facts—The daffodil is the national flower of Wales. It also is often used to depict hope and joy and is the symbol of cancer charities in many countries.⁹

The name Narcissus is believed to have originated from Greek mythology. A handsome youth, Narcissus, fell in love with his own reflection, for which the gods punished him by turning him into a flower.¹⁰

Another theory states that Narcissus is derived from the Greek word narkao (to benumb) due to its narcotic properties. When an open wound is subjected to an extract of the bulb, numbness of the entire nervous system is said to occur as well as paralysis of the heart. This narcotic effect led Socrates to refer to the Narcissus plant as the “chaplet of the infernal gods.”¹¹

Narcissus is an important flower in various ethnic rituals. The Greeks often planted daffodils near tombs. In Muslim culture, white is believed to be the symbol of good and purity; Narcissus was one of the most common white-flowered plants found in Muslim graveyards.¹²

Medicinal Qualities and Uses—Narcissus species have been used as medicinal plants for a variety of ailments. For example, Narcissus tazetta contains flavonoids, alkaloids, saponins, tannins, cardiac glycosides, oil, steroids, terpenoids, and anthraquinones that contribute to its antibacterial, antifungal, antiviral, antimalarial, anticancer, antioxidant, dermatologic, cardiovascular, immunomodulatory, and acetylcholinesterase inhibitory effects.¹³ In a study, chloroform extracts from N tazetta bulbs were found to be more active than doxorubicin against hepatocellular and colon cancer cell lines.¹⁴

More than 500 alkaloids have been isolated from the Narcissus genus.¹⁵ In 2001, the US Food and Drug Administration approved one of the alkaloids, galantamine, for the treatment of mild to moderate stages of Alzheimer disease.¹⁶ Galantamine selectively and reversibly inhibits acetylcholinesterase, the enzyme believed responsible for neurodegeneration seen in Alzheimer disease. Plants are the main source of galantamine, despite the ability of pharmaceutical companies to synthesize the compound. Galantamine hydrobromide is sold by prescription (Razadyne [Janssen Pharmaceuticals, Inc]); generic formulations approved by the US Food and Drug Administration have been produced by more than 15 pharmaceutical companies.^17,18

Irritant and Allergen

Sap found in the bulbs and hollow stems of Narcissus contains calcium oxalate crystals, or raphides. The minute, needle-shaped calcium oxalate crystals are believed to be a waste product of cellular metabolism.¹⁹ When the plant structure is compromised by pickers snapping the stalk, the sharp crystals penetrate the skin to cause an irritant contact dermatitis.

Relevant Research—A study used electron microscopy to characterize the structure of raphides from various plants,² though not from Narcissus species; the structure of each raphide was then compared to the degree of irritation it produced. The researchers concluded that more elongated crystals (those containing barbs) produce a greater degree of irritation. Narcissus species are known to cause varying degrees of skin irritation: For example, N tazetta rarely causes skin irritation, whereas N pseudonarcissi (daffodil) tends to cause remarkably more skin irritation.²

Allergic reactions to and strong toxicity from Narcissus species are not well understood. In a study, only 2 alkaloids—homolycorine and masonin—produced a weakly positive reaction in patch tests on sensitized guinea pigs, which correlates with the finding of a different study, in which only 2 of 12 patients whose findings were examined over 14 years had a positive patch test for Narcissus.^20,21

However, IgE-mediated allergies indicative of an allergic response to Narcissus have been reported. A study isolated an allergenic protein, narcin, from bulbs of N tazetta. Narcin is a 13-kDa protein with potent allergenic effects capable of inducing production of proinflammatory cytokines and increasing IgE levels in mononuclear cells in peripheral blood.²²

More research is required to find and understand the compounds responsible for causing an allergic reaction to Narcissus.

Contact allergy to cobalt, chromium, and especially nickel, may be higher in European metalworkers than in all European male patients with allergic contact dermatitis, a systematic review and meta-analysis reports.

“Metal allergy to all three metals was significantly more common in European metalworkers with dermatitis attending patch test clinics as compared to ESSCA [European Surveillance System on Contact Allergies] data, indicating a relationship to occupational exposures,” senior study author Jeanne D. Johansen, MD, professor, department of dermatology and allergy, Copenhagen University Hospital, Hellerup, Denmark, and colleagues at the University of Copenhagen wrote in Contact Dermatitis. “However, confounders could not be accounted for.”

How common is metal allergy in metalworkers?

Occupational hand eczema is known to be common in metalworkers. Touching oils, greases, metals, leather gloves, rubber materials, and metalworking fluids as they repeatedly cut, shape, and process raw metals and minerals derived from ore mining exposes metalworkers to allergens and skin irritants, the authors wrote. But the prevalence of allergy to certain metals has not been well characterized.

So they searched PubMed for full-text studies in English that reported metal allergy prevalence in metalworkers, from the database’s inception through April 2022.

They included studies with absolute numbers or proportions of metal allergy to cobalt, chromium, or nickel, in all metalworkers with suspected allergic contact dermatitis who attended outpatient clinics or who worked at metalworking plants participating in workplace studies.

The researchers performed a random-effects meta-analysis to calculate the pooled prevalence of metal allergy. Because 85%-90% of metalworkers in Denmark are male, they compared the estimates they found with ESSCA data on 13,382 consecutively patch-tested males with dermatitis between 2015 and 2018.

Of the 1,667 records they screened, they analyzed data from 29 that met their inclusion criteria: 22 patient studies and 7 workplace studies involving 5,691 patients overall from 22 studies from Europe, 5 studies from Asia, and 1 from Africa. Regarding European metalworkers, the authors found:

• Pooled proportions of allergy in European metalworkers with dermatitis referred to patch test clinics were 8.2% to cobalt (95% confidence interval, 5.3%-11.7%), 8.0% to chromium (95% CI, 5.1%-11.4%), and 11.0% to nickel (95% CI, 7.3%-15.4%).
• In workplace studies, the pooled proportions of allergy in unselected European metalworkers were 4.9% to cobalt, (95% CI, 2.4%-8.1%), 5.2% to chromium (95% CI, 1.0% - 12.6%), and 7.6% to nickel (95% CI, 3.8%-12.6%).
• By comparison, ESSCA data on metal allergy prevalence showed 3.9% allergic to cobalt (95% CI, 3.6%-4.2%), 4.4% allergic to chromium (95% CI, 4.1%-4.8%), and 6.7% allergic to nickel (95% CI, 6.3%-7.0%).
• Data on sex, age, body piercings, and atopic dermatitis were scant.

Thorough histories, protective regulations and equipment

Providers need to ask their dermatitis patients about current and past occupations and hobbies, and employers need to provide employees with equipment that protects them from exposure, Kelly Tyler, MD, associate professor of dermatology, Ohio State University Wexner Medical Center, Columbus, said in an interview.

“Repeated exposure to an allergen is required for sensitization to develop,” said Dr. Tyler, who was not involved in the study. “Metalworkers, who are continually exposed to metals and metalworking fluids, have a higher risk of allergic contact dermatitis to cobalt, chromium, and nickel.”

“The primary treatment for allergic contact dermatitis is preventing continued exposure to the allergen,” she added. “This study highlights the importance of asking about metal or metalworking fluid in the workplace and of elucidating whether the employer is providing appropriate protective gear.”

To prevent occupational dermatitis, workplaces need to apply regulatory measures and provide their employees with protective equipment, Dr. Tyler advised.

“Body piercings are a common sensitizer in patients with metal allergy, and the prevalence of body piercings among metalworkers was not included in the study,” she noted.

The results of the study may not be generalizable to patients in the United States, she added, because regulations and requirements to provide protective gear here may differ.

“Taking a thorough patient history is crucial when investigating potential causes of dermatitis, especially in patients with suspected allergic contact dermatitis,” Dr. Tyler urged.

Funding and conflict-of-interest details were not provided. Dr. Tyler reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Contact allergy to cobalt, chromium, and especially nickel, may be higher in European metalworkers than in all European male patients with allergic contact dermatitis, a systematic review and meta-analysis reports.

“Metal allergy to all three metals was significantly more common in European metalworkers with dermatitis attending patch test clinics as compared to ESSCA [European Surveillance System on Contact Allergies] data, indicating a relationship to occupational exposures,” senior study author Jeanne D. Johansen, MD, professor, department of dermatology and allergy, Copenhagen University Hospital, Hellerup, Denmark, and colleagues at the University of Copenhagen wrote in Contact Dermatitis. “However, confounders could not be accounted for.”

How common is metal allergy in metalworkers?

Occupational hand eczema is known to be common in metalworkers. Touching oils, greases, metals, leather gloves, rubber materials, and metalworking fluids as they repeatedly cut, shape, and process raw metals and minerals derived from ore mining exposes metalworkers to allergens and skin irritants, the authors wrote. But the prevalence of allergy to certain metals has not been well characterized.

So they searched PubMed for full-text studies in English that reported metal allergy prevalence in metalworkers, from the database’s inception through April 2022.

They included studies with absolute numbers or proportions of metal allergy to cobalt, chromium, or nickel, in all metalworkers with suspected allergic contact dermatitis who attended outpatient clinics or who worked at metalworking plants participating in workplace studies.

The researchers performed a random-effects meta-analysis to calculate the pooled prevalence of metal allergy. Because 85%-90% of metalworkers in Denmark are male, they compared the estimates they found with ESSCA data on 13,382 consecutively patch-tested males with dermatitis between 2015 and 2018.

Of the 1,667 records they screened, they analyzed data from 29 that met their inclusion criteria: 22 patient studies and 7 workplace studies involving 5,691 patients overall from 22 studies from Europe, 5 studies from Asia, and 1 from Africa. Regarding European metalworkers, the authors found:

• Pooled proportions of allergy in European metalworkers with dermatitis referred to patch test clinics were 8.2% to cobalt (95% confidence interval, 5.3%-11.7%), 8.0% to chromium (95% CI, 5.1%-11.4%), and 11.0% to nickel (95% CI, 7.3%-15.4%).
• In workplace studies, the pooled proportions of allergy in unselected European metalworkers were 4.9% to cobalt, (95% CI, 2.4%-8.1%), 5.2% to chromium (95% CI, 1.0% - 12.6%), and 7.6% to nickel (95% CI, 3.8%-12.6%).
• By comparison, ESSCA data on metal allergy prevalence showed 3.9% allergic to cobalt (95% CI, 3.6%-4.2%), 4.4% allergic to chromium (95% CI, 4.1%-4.8%), and 6.7% allergic to nickel (95% CI, 6.3%-7.0%).
• Data on sex, age, body piercings, and atopic dermatitis were scant.

Thorough histories, protective regulations and equipment

Providers need to ask their dermatitis patients about current and past occupations and hobbies, and employers need to provide employees with equipment that protects them from exposure, Kelly Tyler, MD, associate professor of dermatology, Ohio State University Wexner Medical Center, Columbus, said in an interview.

“Repeated exposure to an allergen is required for sensitization to develop,” said Dr. Tyler, who was not involved in the study. “Metalworkers, who are continually exposed to metals and metalworking fluids, have a higher risk of allergic contact dermatitis to cobalt, chromium, and nickel.”

“The primary treatment for allergic contact dermatitis is preventing continued exposure to the allergen,” she added. “This study highlights the importance of asking about metal or metalworking fluid in the workplace and of elucidating whether the employer is providing appropriate protective gear.”

To prevent occupational dermatitis, workplaces need to apply regulatory measures and provide their employees with protective equipment, Dr. Tyler advised.

“Body piercings are a common sensitizer in patients with metal allergy, and the prevalence of body piercings among metalworkers was not included in the study,” she noted.

The results of the study may not be generalizable to patients in the United States, she added, because regulations and requirements to provide protective gear here may differ.

“Taking a thorough patient history is crucial when investigating potential causes of dermatitis, especially in patients with suspected allergic contact dermatitis,” Dr. Tyler urged.

Funding and conflict-of-interest details were not provided. Dr. Tyler reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Contact allergy to cobalt, chromium, and especially nickel, may be higher in European metalworkers than in all European male patients with allergic contact dermatitis, a systematic review and meta-analysis reports.

“Metal allergy to all three metals was significantly more common in European metalworkers with dermatitis attending patch test clinics as compared to ESSCA [European Surveillance System on Contact Allergies] data, indicating a relationship to occupational exposures,” senior study author Jeanne D. Johansen, MD, professor, department of dermatology and allergy, Copenhagen University Hospital, Hellerup, Denmark, and colleagues at the University of Copenhagen wrote in Contact Dermatitis. “However, confounders could not be accounted for.”

How common is metal allergy in metalworkers?

Occupational hand eczema is known to be common in metalworkers. Touching oils, greases, metals, leather gloves, rubber materials, and metalworking fluids as they repeatedly cut, shape, and process raw metals and minerals derived from ore mining exposes metalworkers to allergens and skin irritants, the authors wrote. But the prevalence of allergy to certain metals has not been well characterized.

So they searched PubMed for full-text studies in English that reported metal allergy prevalence in metalworkers, from the database’s inception through April 2022.

They included studies with absolute numbers or proportions of metal allergy to cobalt, chromium, or nickel, in all metalworkers with suspected allergic contact dermatitis who attended outpatient clinics or who worked at metalworking plants participating in workplace studies.

The researchers performed a random-effects meta-analysis to calculate the pooled prevalence of metal allergy. Because 85%-90% of metalworkers in Denmark are male, they compared the estimates they found with ESSCA data on 13,382 consecutively patch-tested males with dermatitis between 2015 and 2018.

Of the 1,667 records they screened, they analyzed data from 29 that met their inclusion criteria: 22 patient studies and 7 workplace studies involving 5,691 patients overall from 22 studies from Europe, 5 studies from Asia, and 1 from Africa. Regarding European metalworkers, the authors found:

• Pooled proportions of allergy in European metalworkers with dermatitis referred to patch test clinics were 8.2% to cobalt (95% confidence interval, 5.3%-11.7%), 8.0% to chromium (95% CI, 5.1%-11.4%), and 11.0% to nickel (95% CI, 7.3%-15.4%).
• In workplace studies, the pooled proportions of allergy in unselected European metalworkers were 4.9% to cobalt, (95% CI, 2.4%-8.1%), 5.2% to chromium (95% CI, 1.0% - 12.6%), and 7.6% to nickel (95% CI, 3.8%-12.6%).
• By comparison, ESSCA data on metal allergy prevalence showed 3.9% allergic to cobalt (95% CI, 3.6%-4.2%), 4.4% allergic to chromium (95% CI, 4.1%-4.8%), and 6.7% allergic to nickel (95% CI, 6.3%-7.0%).
• Data on sex, age, body piercings, and atopic dermatitis were scant.

Thorough histories, protective regulations and equipment

Providers need to ask their dermatitis patients about current and past occupations and hobbies, and employers need to provide employees with equipment that protects them from exposure, Kelly Tyler, MD, associate professor of dermatology, Ohio State University Wexner Medical Center, Columbus, said in an interview.

“Repeated exposure to an allergen is required for sensitization to develop,” said Dr. Tyler, who was not involved in the study. “Metalworkers, who are continually exposed to metals and metalworking fluids, have a higher risk of allergic contact dermatitis to cobalt, chromium, and nickel.”

“The primary treatment for allergic contact dermatitis is preventing continued exposure to the allergen,” she added. “This study highlights the importance of asking about metal or metalworking fluid in the workplace and of elucidating whether the employer is providing appropriate protective gear.”

To prevent occupational dermatitis, workplaces need to apply regulatory measures and provide their employees with protective equipment, Dr. Tyler advised.

“Body piercings are a common sensitizer in patients with metal allergy, and the prevalence of body piercings among metalworkers was not included in the study,” she noted.

The results of the study may not be generalizable to patients in the United States, she added, because regulations and requirements to provide protective gear here may differ.

“Taking a thorough patient history is crucial when investigating potential causes of dermatitis, especially in patients with suspected allergic contact dermatitis,” Dr. Tyler urged.

Funding and conflict-of-interest details were not provided. Dr. Tyler reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.