There was no difference in major cardiovascular outcomes with the use of two different diuretics – chlorthalidone or hydrochlorothiazide – in the treatment of hypertension in a new large randomized real-world study.

The Diuretic Comparison Project (DCP), which was conducted in more than 13,500 U.S. veterans age 65 years or over, showed almost identical rates of the primary composite endpoint, including myocardial infarction (MI), stroke, noncancer death, hospitalization for acute heart failure, or urgent revascularization, after a median of 2.4 years of follow-up.

There was no difference in any of the individual endpoints or other secondary cardiovascular outcomes.

However, in the subgroup of patients who had a history of MI or stroke (who made up about 10% of the study population), there was a significant reduction in the primary endpoint with chlorthalidone, whereas those without a history of MI or stroke appeared to have an increased risk for primary outcome events while receiving chlorthalidone compared with those receiving hydrochlorothiazide.

The DCP trial was presented at the American Heart Association scientific sessions by Areef Ishani, MD, director of the Minneapolis Primary Care and Specialty Care Integrated Care Community and director of the Veterans Affairs (VA) Midwest Health Care Network.

Asked how to interpret the result for clinical practice, Dr. Ishani said, “I think we can now say that either of these two drugs is appropriate to use for the treatment of hypertension.”

But he added that the decision on what to do with the subgroup of patients with previous MI or stroke was more “challenging.”

“We saw a highly significant benefit in this subgroup, but this was in the context of an overall negative trial,” he noted. “I think this is a discussion with the patients on how they want to hedge their bets. Because these two drugs are so similar, if they wanted to take one or the other because of this subgroup result I think that is a conversation to have, but I think we now need to conduct another trial specifically in this subgroup of patients to see if chlorthalidone really is of benefit in that group.”

Dr. Ishani explained that both chlorthalidone and hydrochlorothiazide have been around for more than 50 years and are considered first-line treatments for hypertension. Early studies suggested better cardiovascular outcomes and 24-hour blood pressure control with chlorthalidone, but recent observational studies have not shown more benefit with chlorthalidone. These studies have suggested that chlorthalidone may be associated with an increase in adverse events, such as hypokalemia, acute kidney injury, and chronic kidney disease.
 

Pragmatic study

The DCP trial was conducted to try to definitively answer this question of whether chlorthalidone is superior to hydrochlorothiazide. The pragmatic study had a “point-of-care” design that allowed participants and health care professionals to know which medication was being prescribed and to administer the medication in a real-world setting.

“Patients can continue with their normal care with their usual care team because we integrated this trial into primary care clinics,” Dr. Ishani said. “We followed participant results using their electronic health record. This study was nonintrusive, cost-effective, and inexpensive. Plus, we were able to recruit a large rural population, which is unusual for large, randomized trials, where we usually rely on big academic medical centers.”

Using VA electronic medical records, the investigators recruited primary care physicians who identified patients older than age 65 years who were receiving hydrochlorothiazide (25 mg or 50 mg) for hypertension. These patients (97% of whom were male) were then randomly assigned to continue receiving hydrochlorothiazide or to switch to an equivalent dose of chlorthalidone. Patients were followed through the electronic medical record as well as Medicare claims and the National Death Index.

Results after a median follow-up of 2.4 years showed no difference in blood pressure control between the two groups.

In terms of clinical events, the primary composite outcome of MI, stroke, noncancer death, hospitalization for acute heart failure, or urgent revascularization occurred in 10.4% of the chlorthalidone group and in 10.0% of the hydrochlorothiazide group (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.94-1.16; P = .4).

There was no difference in any individual components of the primary endpoint or the secondary outcomes of all-cause mortality, any revascularization, or erectile dysfunction.

In terms of adverse events, chlorthalidone was associated with an increase in hypokalemia (6% vs. 4.4%; HR, 1.38), but there was no difference in hospitalization for acute kidney injury.
 

Benefit in MI, stroke subgroup?

In the subgroup analysis, patients with a history of MI or stroke who were receiving chlorthalidone had a significant 27% reduction in the primary endpoint (HR, 0.73; 95% CI, 0.57-0.94). Conversely, patients without a history of MI or stroke appeared to do worse while taking chlorthalidone (HR, 1.12; 95% CI, 1.00-1.26).

“We were surprised by these results,” Dr. Ishani said. “We expected chlorthalidone to be more effective overall. However, learning about these differences in patients who have a history of cardiovascular disease may affect patient care. It’s best for people to talk with their health care clinicians about which of these medications is better for their individual needs.”

He added: “More research is needed to explore these results further because we don’t know how they may fit into treating the general population.”

Dr. Ishani noted that a limitations of this study was that most patients were receiving the low dose of chlorthalidone, and previous studies that suggested benefits with chlorthalidone used the higher dose.

“But the world has voted – we had 4,000 clinicians involved in this study, and the vast majority are using the low dose of hydrochlorothiazide. And this is a definitively negative study,” he said. “The world has also voted in that 10 times more patients were on hydrochlorothiazide than on chlorthalidone.”

Commenting on the study at an AHA press conference, Biykem Bozkurt, MD, PhD, Baylor College of Medicine, Houston, pointed out that in all of the landmark National Institutes of Health hypertension trials, there was a signal for benefit with chlorthalidone compared with other antihypertensives.

Catherine Hackett/MDedge News

“We’ve always had this concept that chlorthalidone is better,” she said. “But this study shows no difference in major cardiovascular endpoints. There was more hypokalemia with chlorthalidone, but that’s recognizable as chlorthalidone is a more potent diuretic.”

Other limitations of the DCP trial are its open-label design, which could interject some bias; the enduring effects of hydrochlorothiazide – most of these patients were receiving this agent as background therapy; and inability to look at the effectiveness of decongestion of the agents in such a pragmatic study, Dr. Bozkurt noted.

She said she would like to see more analysis in the subgroup of patients with previous MI or stroke. “Does this result mean that chlorthalidone is better for sicker patients or is this result just due to chance?” she asked.

“While this study demonstrates equal effectiveness of these two diuretics in the targeted population, the question of subgroups of patients for which we use a more potent diuretic I think remains unanswered,” she concluded.

Designated discussant of the DCP trial at the late-breaking trial session, Daniel Levy, MD, director of the Framingham Heart Study at the National Heart, Lung, and Blood Institute, reminded attendees that chlorthalidone had shown impressive results in previous important hypertension studies including SHEP and ALLHAT.

He said the current DCP was a pragmatic study addressing a knowledge gap that “would never have been performed by industry.”

Dr. Levy concluded that the results showing no difference in outcomes between the two diuretics were “compelling,” although a few questions remain.

These include a possible bias toward hydrochlorothiazide – patients were selected who were already taking that drug and so would have already had a favorable response to it. In addition, because the trial was conducted in an older male population, he questioned whether the results could be generalized to women and younger patients.

The DCP study was funded by the VA Cooperative Studies Program. Dr. Ishani reported no disclosures.

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

There was no difference in major cardiovascular outcomes with the use of two different diuretics – chlorthalidone or hydrochlorothiazide – in the treatment of hypertension in a new large randomized real-world study.

The Diuretic Comparison Project (DCP), which was conducted in more than 13,500 U.S. veterans age 65 years or over, showed almost identical rates of the primary composite endpoint, including myocardial infarction (MI), stroke, noncancer death, hospitalization for acute heart failure, or urgent revascularization, after a median of 2.4 years of follow-up.

There was no difference in any of the individual endpoints or other secondary cardiovascular outcomes.

However, in the subgroup of patients who had a history of MI or stroke (who made up about 10% of the study population), there was a significant reduction in the primary endpoint with chlorthalidone, whereas those without a history of MI or stroke appeared to have an increased risk for primary outcome events while receiving chlorthalidone compared with those receiving hydrochlorothiazide.

The DCP trial was presented at the American Heart Association scientific sessions by Areef Ishani, MD, director of the Minneapolis Primary Care and Specialty Care Integrated Care Community and director of the Veterans Affairs (VA) Midwest Health Care Network.

Asked how to interpret the result for clinical practice, Dr. Ishani said, “I think we can now say that either of these two drugs is appropriate to use for the treatment of hypertension.”

But he added that the decision on what to do with the subgroup of patients with previous MI or stroke was more “challenging.”

“We saw a highly significant benefit in this subgroup, but this was in the context of an overall negative trial,” he noted. “I think this is a discussion with the patients on how they want to hedge their bets. Because these two drugs are so similar, if they wanted to take one or the other because of this subgroup result I think that is a conversation to have, but I think we now need to conduct another trial specifically in this subgroup of patients to see if chlorthalidone really is of benefit in that group.”

Dr. Ishani explained that both chlorthalidone and hydrochlorothiazide have been around for more than 50 years and are considered first-line treatments for hypertension. Early studies suggested better cardiovascular outcomes and 24-hour blood pressure control with chlorthalidone, but recent observational studies have not shown more benefit with chlorthalidone. These studies have suggested that chlorthalidone may be associated with an increase in adverse events, such as hypokalemia, acute kidney injury, and chronic kidney disease.
 

Pragmatic study

The DCP trial was conducted to try to definitively answer this question of whether chlorthalidone is superior to hydrochlorothiazide. The pragmatic study had a “point-of-care” design that allowed participants and health care professionals to know which medication was being prescribed and to administer the medication in a real-world setting.

“Patients can continue with their normal care with their usual care team because we integrated this trial into primary care clinics,” Dr. Ishani said. “We followed participant results using their electronic health record. This study was nonintrusive, cost-effective, and inexpensive. Plus, we were able to recruit a large rural population, which is unusual for large, randomized trials, where we usually rely on big academic medical centers.”

Using VA electronic medical records, the investigators recruited primary care physicians who identified patients older than age 65 years who were receiving hydrochlorothiazide (25 mg or 50 mg) for hypertension. These patients (97% of whom were male) were then randomly assigned to continue receiving hydrochlorothiazide or to switch to an equivalent dose of chlorthalidone. Patients were followed through the electronic medical record as well as Medicare claims and the National Death Index.

Results after a median follow-up of 2.4 years showed no difference in blood pressure control between the two groups.

In terms of clinical events, the primary composite outcome of MI, stroke, noncancer death, hospitalization for acute heart failure, or urgent revascularization occurred in 10.4% of the chlorthalidone group and in 10.0% of the hydrochlorothiazide group (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.94-1.16; P = .4).

There was no difference in any individual components of the primary endpoint or the secondary outcomes of all-cause mortality, any revascularization, or erectile dysfunction.

In terms of adverse events, chlorthalidone was associated with an increase in hypokalemia (6% vs. 4.4%; HR, 1.38), but there was no difference in hospitalization for acute kidney injury.
 

Benefit in MI, stroke subgroup?

In the subgroup analysis, patients with a history of MI or stroke who were receiving chlorthalidone had a significant 27% reduction in the primary endpoint (HR, 0.73; 95% CI, 0.57-0.94). Conversely, patients without a history of MI or stroke appeared to do worse while taking chlorthalidone (HR, 1.12; 95% CI, 1.00-1.26).

“We were surprised by these results,” Dr. Ishani said. “We expected chlorthalidone to be more effective overall. However, learning about these differences in patients who have a history of cardiovascular disease may affect patient care. It’s best for people to talk with their health care clinicians about which of these medications is better for their individual needs.”

He added: “More research is needed to explore these results further because we don’t know how they may fit into treating the general population.”

Dr. Ishani noted that a limitations of this study was that most patients were receiving the low dose of chlorthalidone, and previous studies that suggested benefits with chlorthalidone used the higher dose.

“But the world has voted – we had 4,000 clinicians involved in this study, and the vast majority are using the low dose of hydrochlorothiazide. And this is a definitively negative study,” he said. “The world has also voted in that 10 times more patients were on hydrochlorothiazide than on chlorthalidone.”

Commenting on the study at an AHA press conference, Biykem Bozkurt, MD, PhD, Baylor College of Medicine, Houston, pointed out that in all of the landmark National Institutes of Health hypertension trials, there was a signal for benefit with chlorthalidone compared with other antihypertensives.

Catherine Hackett/MDedge News

“We’ve always had this concept that chlorthalidone is better,” she said. “But this study shows no difference in major cardiovascular endpoints. There was more hypokalemia with chlorthalidone, but that’s recognizable as chlorthalidone is a more potent diuretic.”

Other limitations of the DCP trial are its open-label design, which could interject some bias; the enduring effects of hydrochlorothiazide – most of these patients were receiving this agent as background therapy; and inability to look at the effectiveness of decongestion of the agents in such a pragmatic study, Dr. Bozkurt noted.

She said she would like to see more analysis in the subgroup of patients with previous MI or stroke. “Does this result mean that chlorthalidone is better for sicker patients or is this result just due to chance?” she asked.

“While this study demonstrates equal effectiveness of these two diuretics in the targeted population, the question of subgroups of patients for which we use a more potent diuretic I think remains unanswered,” she concluded.

Designated discussant of the DCP trial at the late-breaking trial session, Daniel Levy, MD, director of the Framingham Heart Study at the National Heart, Lung, and Blood Institute, reminded attendees that chlorthalidone had shown impressive results in previous important hypertension studies including SHEP and ALLHAT.

He said the current DCP was a pragmatic study addressing a knowledge gap that “would never have been performed by industry.”

Dr. Levy concluded that the results showing no difference in outcomes between the two diuretics were “compelling,” although a few questions remain.

These include a possible bias toward hydrochlorothiazide – patients were selected who were already taking that drug and so would have already had a favorable response to it. In addition, because the trial was conducted in an older male population, he questioned whether the results could be generalized to women and younger patients.

The DCP study was funded by the VA Cooperative Studies Program. Dr. Ishani reported no disclosures.

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

There was no difference in major cardiovascular outcomes with the use of two different diuretics – chlorthalidone or hydrochlorothiazide – in the treatment of hypertension in a new large randomized real-world study.

The Diuretic Comparison Project (DCP), which was conducted in more than 13,500 U.S. veterans age 65 years or over, showed almost identical rates of the primary composite endpoint, including myocardial infarction (MI), stroke, noncancer death, hospitalization for acute heart failure, or urgent revascularization, after a median of 2.4 years of follow-up.

There was no difference in any of the individual endpoints or other secondary cardiovascular outcomes.

However, in the subgroup of patients who had a history of MI or stroke (who made up about 10% of the study population), there was a significant reduction in the primary endpoint with chlorthalidone, whereas those without a history of MI or stroke appeared to have an increased risk for primary outcome events while receiving chlorthalidone compared with those receiving hydrochlorothiazide.

The DCP trial was presented at the American Heart Association scientific sessions by Areef Ishani, MD, director of the Minneapolis Primary Care and Specialty Care Integrated Care Community and director of the Veterans Affairs (VA) Midwest Health Care Network.

Asked how to interpret the result for clinical practice, Dr. Ishani said, “I think we can now say that either of these two drugs is appropriate to use for the treatment of hypertension.”

But he added that the decision on what to do with the subgroup of patients with previous MI or stroke was more “challenging.”

“We saw a highly significant benefit in this subgroup, but this was in the context of an overall negative trial,” he noted. “I think this is a discussion with the patients on how they want to hedge their bets. Because these two drugs are so similar, if they wanted to take one or the other because of this subgroup result I think that is a conversation to have, but I think we now need to conduct another trial specifically in this subgroup of patients to see if chlorthalidone really is of benefit in that group.”

Dr. Ishani explained that both chlorthalidone and hydrochlorothiazide have been around for more than 50 years and are considered first-line treatments for hypertension. Early studies suggested better cardiovascular outcomes and 24-hour blood pressure control with chlorthalidone, but recent observational studies have not shown more benefit with chlorthalidone. These studies have suggested that chlorthalidone may be associated with an increase in adverse events, such as hypokalemia, acute kidney injury, and chronic kidney disease.
 

Pragmatic study

The DCP trial was conducted to try to definitively answer this question of whether chlorthalidone is superior to hydrochlorothiazide. The pragmatic study had a “point-of-care” design that allowed participants and health care professionals to know which medication was being prescribed and to administer the medication in a real-world setting.

“Patients can continue with their normal care with their usual care team because we integrated this trial into primary care clinics,” Dr. Ishani said. “We followed participant results using their electronic health record. This study was nonintrusive, cost-effective, and inexpensive. Plus, we were able to recruit a large rural population, which is unusual for large, randomized trials, where we usually rely on big academic medical centers.”

Using VA electronic medical records, the investigators recruited primary care physicians who identified patients older than age 65 years who were receiving hydrochlorothiazide (25 mg or 50 mg) for hypertension. These patients (97% of whom were male) were then randomly assigned to continue receiving hydrochlorothiazide or to switch to an equivalent dose of chlorthalidone. Patients were followed through the electronic medical record as well as Medicare claims and the National Death Index.

Results after a median follow-up of 2.4 years showed no difference in blood pressure control between the two groups.

In terms of clinical events, the primary composite outcome of MI, stroke, noncancer death, hospitalization for acute heart failure, or urgent revascularization occurred in 10.4% of the chlorthalidone group and in 10.0% of the hydrochlorothiazide group (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.94-1.16; P = .4).

There was no difference in any individual components of the primary endpoint or the secondary outcomes of all-cause mortality, any revascularization, or erectile dysfunction.

In terms of adverse events, chlorthalidone was associated with an increase in hypokalemia (6% vs. 4.4%; HR, 1.38), but there was no difference in hospitalization for acute kidney injury.
 

Benefit in MI, stroke subgroup?

In the subgroup analysis, patients with a history of MI or stroke who were receiving chlorthalidone had a significant 27% reduction in the primary endpoint (HR, 0.73; 95% CI, 0.57-0.94). Conversely, patients without a history of MI or stroke appeared to do worse while taking chlorthalidone (HR, 1.12; 95% CI, 1.00-1.26).

“We were surprised by these results,” Dr. Ishani said. “We expected chlorthalidone to be more effective overall. However, learning about these differences in patients who have a history of cardiovascular disease may affect patient care. It’s best for people to talk with their health care clinicians about which of these medications is better for their individual needs.”

He added: “More research is needed to explore these results further because we don’t know how they may fit into treating the general population.”

Dr. Ishani noted that a limitations of this study was that most patients were receiving the low dose of chlorthalidone, and previous studies that suggested benefits with chlorthalidone used the higher dose.

“But the world has voted – we had 4,000 clinicians involved in this study, and the vast majority are using the low dose of hydrochlorothiazide. And this is a definitively negative study,” he said. “The world has also voted in that 10 times more patients were on hydrochlorothiazide than on chlorthalidone.”

Commenting on the study at an AHA press conference, Biykem Bozkurt, MD, PhD, Baylor College of Medicine, Houston, pointed out that in all of the landmark National Institutes of Health hypertension trials, there was a signal for benefit with chlorthalidone compared with other antihypertensives.

Catherine Hackett/MDedge News

“We’ve always had this concept that chlorthalidone is better,” she said. “But this study shows no difference in major cardiovascular endpoints. There was more hypokalemia with chlorthalidone, but that’s recognizable as chlorthalidone is a more potent diuretic.”

Other limitations of the DCP trial are its open-label design, which could interject some bias; the enduring effects of hydrochlorothiazide – most of these patients were receiving this agent as background therapy; and inability to look at the effectiveness of decongestion of the agents in such a pragmatic study, Dr. Bozkurt noted.

She said she would like to see more analysis in the subgroup of patients with previous MI or stroke. “Does this result mean that chlorthalidone is better for sicker patients or is this result just due to chance?” she asked.

“While this study demonstrates equal effectiveness of these two diuretics in the targeted population, the question of subgroups of patients for which we use a more potent diuretic I think remains unanswered,” she concluded.

Designated discussant of the DCP trial at the late-breaking trial session, Daniel Levy, MD, director of the Framingham Heart Study at the National Heart, Lung, and Blood Institute, reminded attendees that chlorthalidone had shown impressive results in previous important hypertension studies including SHEP and ALLHAT.

He said the current DCP was a pragmatic study addressing a knowledge gap that “would never have been performed by industry.”

Dr. Levy concluded that the results showing no difference in outcomes between the two diuretics were “compelling,” although a few questions remain.

These include a possible bias toward hydrochlorothiazide – patients were selected who were already taking that drug and so would have already had a favorable response to it. In addition, because the trial was conducted in an older male population, he questioned whether the results could be generalized to women and younger patients.

The DCP study was funded by the VA Cooperative Studies Program. Dr. Ishani reported no disclosures.

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

CHICAGO – Despite a 25% reduction in triglycerides (TGs) along with similar reductions in very-low-density lipoprotein (VLDL), and remnant cholesterol, a novel agent failed to provide any protection in a multinational trial against a composite endpoint of major adverse cardiovascular events (MACE) in patients with type 2 diabetes.

“Our data further highlight the complexity of lipid mediators of residual risk among patients with insulin resistance who are receiving statin therapy,” reported Aruna Das Pradhan, MD, of Harvard Medical School, Boston, and Queen Mary University, London.

Ted Bosworth/MDedge News

No benefit from fibrates seen in statin era

“We have not seen a significant cardiovascular event reduction with a fibrate in the statin era,” according to Karol Watson, MD, PhD, director of the UCLA Women’s Cardiovascular Health Center, Los Angeles.

Ted Bosworth/MDedge News

Lipid profile improved as predicted

Yet, in regard to an improvement in the lipid profile, pemafibrate performed as predicted. When compared to placebo 4 months into the trial, pemafibrate was associated with median reductions of 26.2% in TGs, 25.8% in VLDL, and 25.6% in remnant cholesterol, which is cholesterol transported in TG-rich lipoproteins after lipolysis and lipoprotein remodeling.

Furthermore, pemafibrate was associated with a median 27.6% reduction relative to placebo in apolipoprotein C-III and a median 4.8% reduction in apolipoprotein E, all of which would be expected to reduce CV risk.

The findings of PROMINENT were published online in the New England Journal of Medicine immediately after their presentation.

The findings of this study do not eliminate any hope for lowering residual CV risk with TG reductions, but they do suggest the relationship with other lipid subfractions is complex, according to Salim S. Virani, MD, PhD, a professor of cardiology at Baylor College of Medicine, Houston.

“I think that the lack of efficacy despite TG lowering may be largely due to a lack of an overall decrease in the apolipoprotein B level,” speculated Dr. Virani, who wrote an editorial that accompanied publication of the PROMINENT results.

He noted that pemafibrate is implicated in converting remnant cholesterol to LDL cholesterol, which might be one reason for a counterproductive effect on CV risk.

“In order for therapies that lower TG levels to be effective, they probably have to have mechanisms to increase clearance of TG-rich remnant lipoprotein cholesterol particles rather than just converting remnant lipoproteins to LDL,” Dr. Virani explained in an attempt to unravel the interplay of these variables.

Although this study enrolled patients “who would be predicted to have the most benefit from a TG-lowering strategy,” Dr. Watson agreed that these results do not necessarily extend to other means of lowering TG. However, it might draw into question the value of pemafibrate and perhaps other drugs in this class for treatment of hypertriglyceridemia. In addition to a lack of CV benefit, treatment was not without risks, including a higher rate of thromboembolism and adverse renal events.

Dr. Das Pradhan reported financial relationships with Denka, Medtelligence, Optum, Novo Nordisk, and Kowa, which provided funding for this trial. Dr. Watson reported financial relationships with Amarin, Amgen, Boehringer-Ingelheim, and Esperion.

CHICAGO – Despite a 25% reduction in triglycerides (TGs) along with similar reductions in very-low-density lipoprotein (VLDL), and remnant cholesterol, a novel agent failed to provide any protection in a multinational trial against a composite endpoint of major adverse cardiovascular events (MACE) in patients with type 2 diabetes.

“Our data further highlight the complexity of lipid mediators of residual risk among patients with insulin resistance who are receiving statin therapy,” reported Aruna Das Pradhan, MD, of Harvard Medical School, Boston, and Queen Mary University, London.

Ted Bosworth/MDedge News

No benefit from fibrates seen in statin era

“We have not seen a significant cardiovascular event reduction with a fibrate in the statin era,” according to Karol Watson, MD, PhD, director of the UCLA Women’s Cardiovascular Health Center, Los Angeles.

Ted Bosworth/MDedge News

Lipid profile improved as predicted

Yet, in regard to an improvement in the lipid profile, pemafibrate performed as predicted. When compared to placebo 4 months into the trial, pemafibrate was associated with median reductions of 26.2% in TGs, 25.8% in VLDL, and 25.6% in remnant cholesterol, which is cholesterol transported in TG-rich lipoproteins after lipolysis and lipoprotein remodeling.

Furthermore, pemafibrate was associated with a median 27.6% reduction relative to placebo in apolipoprotein C-III and a median 4.8% reduction in apolipoprotein E, all of which would be expected to reduce CV risk.

The findings of PROMINENT were published online in the New England Journal of Medicine immediately after their presentation.

The findings of this study do not eliminate any hope for lowering residual CV risk with TG reductions, but they do suggest the relationship with other lipid subfractions is complex, according to Salim S. Virani, MD, PhD, a professor of cardiology at Baylor College of Medicine, Houston.

“I think that the lack of efficacy despite TG lowering may be largely due to a lack of an overall decrease in the apolipoprotein B level,” speculated Dr. Virani, who wrote an editorial that accompanied publication of the PROMINENT results.

He noted that pemafibrate is implicated in converting remnant cholesterol to LDL cholesterol, which might be one reason for a counterproductive effect on CV risk.

“In order for therapies that lower TG levels to be effective, they probably have to have mechanisms to increase clearance of TG-rich remnant lipoprotein cholesterol particles rather than just converting remnant lipoproteins to LDL,” Dr. Virani explained in an attempt to unravel the interplay of these variables.

Although this study enrolled patients “who would be predicted to have the most benefit from a TG-lowering strategy,” Dr. Watson agreed that these results do not necessarily extend to other means of lowering TG. However, it might draw into question the value of pemafibrate and perhaps other drugs in this class for treatment of hypertriglyceridemia. In addition to a lack of CV benefit, treatment was not without risks, including a higher rate of thromboembolism and adverse renal events.

Dr. Das Pradhan reported financial relationships with Denka, Medtelligence, Optum, Novo Nordisk, and Kowa, which provided funding for this trial. Dr. Watson reported financial relationships with Amarin, Amgen, Boehringer-Ingelheim, and Esperion.

CHICAGO – Despite a 25% reduction in triglycerides (TGs) along with similar reductions in very-low-density lipoprotein (VLDL), and remnant cholesterol, a novel agent failed to provide any protection in a multinational trial against a composite endpoint of major adverse cardiovascular events (MACE) in patients with type 2 diabetes.

“Our data further highlight the complexity of lipid mediators of residual risk among patients with insulin resistance who are receiving statin therapy,” reported Aruna Das Pradhan, MD, of Harvard Medical School, Boston, and Queen Mary University, London.

Ted Bosworth/MDedge News

No benefit from fibrates seen in statin era

“We have not seen a significant cardiovascular event reduction with a fibrate in the statin era,” according to Karol Watson, MD, PhD, director of the UCLA Women’s Cardiovascular Health Center, Los Angeles.

Ted Bosworth/MDedge News

Lipid profile improved as predicted

Yet, in regard to an improvement in the lipid profile, pemafibrate performed as predicted. When compared to placebo 4 months into the trial, pemafibrate was associated with median reductions of 26.2% in TGs, 25.8% in VLDL, and 25.6% in remnant cholesterol, which is cholesterol transported in TG-rich lipoproteins after lipolysis and lipoprotein remodeling.

Furthermore, pemafibrate was associated with a median 27.6% reduction relative to placebo in apolipoprotein C-III and a median 4.8% reduction in apolipoprotein E, all of which would be expected to reduce CV risk.

The findings of PROMINENT were published online in the New England Journal of Medicine immediately after their presentation.

The findings of this study do not eliminate any hope for lowering residual CV risk with TG reductions, but they do suggest the relationship with other lipid subfractions is complex, according to Salim S. Virani, MD, PhD, a professor of cardiology at Baylor College of Medicine, Houston.

“I think that the lack of efficacy despite TG lowering may be largely due to a lack of an overall decrease in the apolipoprotein B level,” speculated Dr. Virani, who wrote an editorial that accompanied publication of the PROMINENT results.

He noted that pemafibrate is implicated in converting remnant cholesterol to LDL cholesterol, which might be one reason for a counterproductive effect on CV risk.

“In order for therapies that lower TG levels to be effective, they probably have to have mechanisms to increase clearance of TG-rich remnant lipoprotein cholesterol particles rather than just converting remnant lipoproteins to LDL,” Dr. Virani explained in an attempt to unravel the interplay of these variables.

Although this study enrolled patients “who would be predicted to have the most benefit from a TG-lowering strategy,” Dr. Watson agreed that these results do not necessarily extend to other means of lowering TG. However, it might draw into question the value of pemafibrate and perhaps other drugs in this class for treatment of hypertriglyceridemia. In addition to a lack of CV benefit, treatment was not without risks, including a higher rate of thromboembolism and adverse renal events.

Dr. Das Pradhan reported financial relationships with Denka, Medtelligence, Optum, Novo Nordisk, and Kowa, which provided funding for this trial. Dr. Watson reported financial relationships with Amarin, Amgen, Boehringer-Ingelheim, and Esperion.

When compared with the general population, hairdressers experience an excess risk of contact allergy linked to hair cosmetic ingredients, a systematic review suggests.

“Research has shown that up to 70% of hairdressers suffer from work-related skin damage, mostly hand dermatitis, at some point during their career,” write Wolfgang Uter of Friedrich-Alexander University Erlangen-Nürnberg and coauthors. In general, they write, occupational skin diseases such as hand dermatitis represent up to 35% of reported occupational diseases. The study was published online in Contact Dermatitis.

Wet work and skin contact with detergents and hairdressing chemicals are top risk factors for developing occupational skin disease in this population, according to the researchers.

To further understand the burden of occupational contact allergy in hairdressers, the investigators gathered evidence published since 2000 on contact allergies to hair cosmetic chemicals. They searched the literature for nine substances selected beforehand by experts and stakeholders. The researchers also examined the prevalence of sensitization between hairdressers and other individuals given skin patch tests.
 

Substance by substance

Common potentially sensitizing cosmetic ingredients reported across studies included p-phenylenediamine (PPD), persulfates (mostly ammonium persulfate [APS]), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG).

In a pooled analysis, the overall prevalence of contact allergy to PPD was 4.3% in consecutively patch-tested patients, but in hairdressers specifically, the overall prevalence of contact allergy to this ingredient was 28.6%, reviewers reported.

The pooled prevalence of contact allergy to APS was 5.5% in consumers and 17.2% in hairdressers. In other review studies, contact allergy risks to APS, GMTG, and ATG were also elevated in hairdressers compared with all controls.

The calculated relative risk (RR) of contact allergy to PPD was approximately 5.4 higher for hairdressers, while the RR for ATG sensitization was 3.4 in hairdressers compared with consumers.

Commenting on these findings, James A. Yiannias, MD, professor of dermatology at the Mayo Medical School, Phoenix, told this news organization in an email that many providers and patients are concerned only about hair dye molecules such as PPD and aminophenol, as well as permanent, wave, and straightening chemicals such as GMTG.

“Although these are common allergens in hairdressers, allergens such as fragrances and some preservatives found in daily hair care products such as shampoos, conditioners, and hair sprays are also common causes of contact dermatitis,” said Dr. Yiannias, who wasn’t involved in the research.

Consequences of exposure

Dr. Yiannias explained that progressive worsening of the dermatitis can occur with ongoing allergen exposure and, if not properly mitigated, can lead to bigger issues. “Initial nuisances of mild irritation and hyperkeratosis can evolve to a state of fissuring with the risk of bleeding and significant pain,” he said.

But once severe and untreated dermatitis occurs, Dr. Yiannias said that hairdressers “may need to change careers” or at least face short- or long-term unemployment.

The researchers suggest reducing exposure to the allergen is key for prevention of symptoms, adding that adequate guidance on the safe use of new products is needed. Also, the researchers suggested that vocational schools should more rigorously implement education for hairdressers that addresses how to protect the skin appropriately at work.

“Hairdressers are taught during their training to be cautious about allergen exposure by avoiding touching high-risk ingredients such as hair dyes,” Dr. Yiannias added. “However, in practice, this is very difficult since the wearing of gloves can impair the tactile sensations that hairdressers often feel is essential in performing their job.”

The study received no industry funding. Dr. Yiannias reports no relevant financial relationships.

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

When compared with the general population, hairdressers experience an excess risk of contact allergy linked to hair cosmetic ingredients, a systematic review suggests.

“Research has shown that up to 70% of hairdressers suffer from work-related skin damage, mostly hand dermatitis, at some point during their career,” write Wolfgang Uter of Friedrich-Alexander University Erlangen-Nürnberg and coauthors. In general, they write, occupational skin diseases such as hand dermatitis represent up to 35% of reported occupational diseases. The study was published online in Contact Dermatitis.

Wet work and skin contact with detergents and hairdressing chemicals are top risk factors for developing occupational skin disease in this population, according to the researchers.

To further understand the burden of occupational contact allergy in hairdressers, the investigators gathered evidence published since 2000 on contact allergies to hair cosmetic chemicals. They searched the literature for nine substances selected beforehand by experts and stakeholders. The researchers also examined the prevalence of sensitization between hairdressers and other individuals given skin patch tests.
 

Substance by substance

Common potentially sensitizing cosmetic ingredients reported across studies included p-phenylenediamine (PPD), persulfates (mostly ammonium persulfate [APS]), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG).

In a pooled analysis, the overall prevalence of contact allergy to PPD was 4.3% in consecutively patch-tested patients, but in hairdressers specifically, the overall prevalence of contact allergy to this ingredient was 28.6%, reviewers reported.

The pooled prevalence of contact allergy to APS was 5.5% in consumers and 17.2% in hairdressers. In other review studies, contact allergy risks to APS, GMTG, and ATG were also elevated in hairdressers compared with all controls.

The calculated relative risk (RR) of contact allergy to PPD was approximately 5.4 higher for hairdressers, while the RR for ATG sensitization was 3.4 in hairdressers compared with consumers.

Commenting on these findings, James A. Yiannias, MD, professor of dermatology at the Mayo Medical School, Phoenix, told this news organization in an email that many providers and patients are concerned only about hair dye molecules such as PPD and aminophenol, as well as permanent, wave, and straightening chemicals such as GMTG.

“Although these are common allergens in hairdressers, allergens such as fragrances and some preservatives found in daily hair care products such as shampoos, conditioners, and hair sprays are also common causes of contact dermatitis,” said Dr. Yiannias, who wasn’t involved in the research.

Consequences of exposure

Dr. Yiannias explained that progressive worsening of the dermatitis can occur with ongoing allergen exposure and, if not properly mitigated, can lead to bigger issues. “Initial nuisances of mild irritation and hyperkeratosis can evolve to a state of fissuring with the risk of bleeding and significant pain,” he said.

But once severe and untreated dermatitis occurs, Dr. Yiannias said that hairdressers “may need to change careers” or at least face short- or long-term unemployment.

The researchers suggest reducing exposure to the allergen is key for prevention of symptoms, adding that adequate guidance on the safe use of new products is needed. Also, the researchers suggested that vocational schools should more rigorously implement education for hairdressers that addresses how to protect the skin appropriately at work.

“Hairdressers are taught during their training to be cautious about allergen exposure by avoiding touching high-risk ingredients such as hair dyes,” Dr. Yiannias added. “However, in practice, this is very difficult since the wearing of gloves can impair the tactile sensations that hairdressers often feel is essential in performing their job.”

The study received no industry funding. Dr. Yiannias reports no relevant financial relationships.

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

When compared with the general population, hairdressers experience an excess risk of contact allergy linked to hair cosmetic ingredients, a systematic review suggests.

“Research has shown that up to 70% of hairdressers suffer from work-related skin damage, mostly hand dermatitis, at some point during their career,” write Wolfgang Uter of Friedrich-Alexander University Erlangen-Nürnberg and coauthors. In general, they write, occupational skin diseases such as hand dermatitis represent up to 35% of reported occupational diseases. The study was published online in Contact Dermatitis.

Wet work and skin contact with detergents and hairdressing chemicals are top risk factors for developing occupational skin disease in this population, according to the researchers.

To further understand the burden of occupational contact allergy in hairdressers, the investigators gathered evidence published since 2000 on contact allergies to hair cosmetic chemicals. They searched the literature for nine substances selected beforehand by experts and stakeholders. The researchers also examined the prevalence of sensitization between hairdressers and other individuals given skin patch tests.
 

Substance by substance

Common potentially sensitizing cosmetic ingredients reported across studies included p-phenylenediamine (PPD), persulfates (mostly ammonium persulfate [APS]), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG).

In a pooled analysis, the overall prevalence of contact allergy to PPD was 4.3% in consecutively patch-tested patients, but in hairdressers specifically, the overall prevalence of contact allergy to this ingredient was 28.6%, reviewers reported.

The pooled prevalence of contact allergy to APS was 5.5% in consumers and 17.2% in hairdressers. In other review studies, contact allergy risks to APS, GMTG, and ATG were also elevated in hairdressers compared with all controls.

The calculated relative risk (RR) of contact allergy to PPD was approximately 5.4 higher for hairdressers, while the RR for ATG sensitization was 3.4 in hairdressers compared with consumers.

Commenting on these findings, James A. Yiannias, MD, professor of dermatology at the Mayo Medical School, Phoenix, told this news organization in an email that many providers and patients are concerned only about hair dye molecules such as PPD and aminophenol, as well as permanent, wave, and straightening chemicals such as GMTG.

“Although these are common allergens in hairdressers, allergens such as fragrances and some preservatives found in daily hair care products such as shampoos, conditioners, and hair sprays are also common causes of contact dermatitis,” said Dr. Yiannias, who wasn’t involved in the research.

Consequences of exposure

Dr. Yiannias explained that progressive worsening of the dermatitis can occur with ongoing allergen exposure and, if not properly mitigated, can lead to bigger issues. “Initial nuisances of mild irritation and hyperkeratosis can evolve to a state of fissuring with the risk of bleeding and significant pain,” he said.

But once severe and untreated dermatitis occurs, Dr. Yiannias said that hairdressers “may need to change careers” or at least face short- or long-term unemployment.

The researchers suggest reducing exposure to the allergen is key for prevention of symptoms, adding that adequate guidance on the safe use of new products is needed. Also, the researchers suggested that vocational schools should more rigorously implement education for hairdressers that addresses how to protect the skin appropriately at work.

“Hairdressers are taught during their training to be cautious about allergen exposure by avoiding touching high-risk ingredients such as hair dyes,” Dr. Yiannias added. “However, in practice, this is very difficult since the wearing of gloves can impair the tactile sensations that hairdressers often feel is essential in performing their job.”

The study received no industry funding. Dr. Yiannias reports no relevant financial relationships.

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

I suspect that you have heard about or maybe read the recent Associated Press story reporting that four daycare workers in Hamilton, Miss., have been charged with felony child abuse for intentionally scaring the children “who didn’t clean up or act good” by wearing a Halloween mask and yelling in their faces. I can have some sympathy for those among us who choose to spend their days tending a flock of sometimes unruly and mischievous toddlers and preschoolers. But, I think one would be hard pressed to find very many adults who would condone the strategy of these misguided daycare providers. Not surprisingly, the parents of some of these children describe their children as traumatized and having disordered sleep.

The news report of this incident in Mississippi doesn’t tell us if these daycare providers had used this tactic in the past. One wonders whether they had found less dramatic verbal threats just weren’t as effective as they had hoped and so decided to go all out.

How effective is fear in changing behavior? Certainly, we have all experienced situations in which a frightening experience has caused us to avoid places, people, and activities. But, is a fear-focused strategy one that health care providers should include in their quiver as we try to mold patient behavior? As luck would have it, 2 weeks before this news story broke I encountered a global study from 84 countries that sought to answer this question (Affect Sci. 2022 Sep. doi: 10.1007/s42761-022-00128-3).

Using the WHO four-point advice about COVID prevention (stay home/avoid shops/use face covering/isolate if exposed) as a model the researchers around the world reviewed the responses of 16,000 individuals. They found that there was no difference in the effectiveness of the message whether it was framed as a negative (“you have so much to lose”) or a positive (“you have so much to gain”). However, investigators observed that the negatively framed presentations generated significantly more anxiety in the respondents. The authors of the paper conclude that if there is no significant difference in the effectiveness, why would we chose a negatively framed presentation that is likely to generate anxiety that we know is associated with increased morbidity and mortality. From a purely public health perspective, it doesn’t make sense and is counterproductive.

I guess if we look back to the old carrot and stick metaphor we shouldn’t be surprised by the findings in this paper. If one’s only goal is to get a group of young preschoolers to behave by scaring the b’geezes out of them with a mask or a threat of bodily punishment, then go for it. Scare tactics will probably work just as well as offering a well-chosen reward system. However, the devil is in the side effects. It’s the same argument that I give to parents who argue that spanking works. Of course it does, but it has a narrow margin for safety and can set up ripples of negative side effects that can destroy healthy parent-child relationships.

The bottom line of this story is the sad truth that somewhere along the line someone failed to effectively train these four daycare workers. But, do we as health care providers need to rethink our training? Have we forgotten our commitment to “First do no harm?” As we craft our messaging have we thought enough about the potential side effects of our attempts at scaring the public into following our suggestions?

Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Other than a Littman stethoscope he accepted as a first-year medical student in 1966, Dr. Wilkoff reports having nothing to disclose. Email him at [email protected].

I suspect that you have heard about or maybe read the recent Associated Press story reporting that four daycare workers in Hamilton, Miss., have been charged with felony child abuse for intentionally scaring the children “who didn’t clean up or act good” by wearing a Halloween mask and yelling in their faces. I can have some sympathy for those among us who choose to spend their days tending a flock of sometimes unruly and mischievous toddlers and preschoolers. But, I think one would be hard pressed to find very many adults who would condone the strategy of these misguided daycare providers. Not surprisingly, the parents of some of these children describe their children as traumatized and having disordered sleep.

The news report of this incident in Mississippi doesn’t tell us if these daycare providers had used this tactic in the past. One wonders whether they had found less dramatic verbal threats just weren’t as effective as they had hoped and so decided to go all out.

How effective is fear in changing behavior? Certainly, we have all experienced situations in which a frightening experience has caused us to avoid places, people, and activities. But, is a fear-focused strategy one that health care providers should include in their quiver as we try to mold patient behavior? As luck would have it, 2 weeks before this news story broke I encountered a global study from 84 countries that sought to answer this question (Affect Sci. 2022 Sep. doi: 10.1007/s42761-022-00128-3).

Using the WHO four-point advice about COVID prevention (stay home/avoid shops/use face covering/isolate if exposed) as a model the researchers around the world reviewed the responses of 16,000 individuals. They found that there was no difference in the effectiveness of the message whether it was framed as a negative (“you have so much to lose”) or a positive (“you have so much to gain”). However, investigators observed that the negatively framed presentations generated significantly more anxiety in the respondents. The authors of the paper conclude that if there is no significant difference in the effectiveness, why would we chose a negatively framed presentation that is likely to generate anxiety that we know is associated with increased morbidity and mortality. From a purely public health perspective, it doesn’t make sense and is counterproductive.

I guess if we look back to the old carrot and stick metaphor we shouldn’t be surprised by the findings in this paper. If one’s only goal is to get a group of young preschoolers to behave by scaring the b’geezes out of them with a mask or a threat of bodily punishment, then go for it. Scare tactics will probably work just as well as offering a well-chosen reward system. However, the devil is in the side effects. It’s the same argument that I give to parents who argue that spanking works. Of course it does, but it has a narrow margin for safety and can set up ripples of negative side effects that can destroy healthy parent-child relationships.

The bottom line of this story is the sad truth that somewhere along the line someone failed to effectively train these four daycare workers. But, do we as health care providers need to rethink our training? Have we forgotten our commitment to “First do no harm?” As we craft our messaging have we thought enough about the potential side effects of our attempts at scaring the public into following our suggestions?

Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Other than a Littman stethoscope he accepted as a first-year medical student in 1966, Dr. Wilkoff reports having nothing to disclose. Email him at [email protected].

I suspect that you have heard about or maybe read the recent Associated Press story reporting that four daycare workers in Hamilton, Miss., have been charged with felony child abuse for intentionally scaring the children “who didn’t clean up or act good” by wearing a Halloween mask and yelling in their faces. I can have some sympathy for those among us who choose to spend their days tending a flock of sometimes unruly and mischievous toddlers and preschoolers. But, I think one would be hard pressed to find very many adults who would condone the strategy of these misguided daycare providers. Not surprisingly, the parents of some of these children describe their children as traumatized and having disordered sleep.

The news report of this incident in Mississippi doesn’t tell us if these daycare providers had used this tactic in the past. One wonders whether they had found less dramatic verbal threats just weren’t as effective as they had hoped and so decided to go all out.

How effective is fear in changing behavior? Certainly, we have all experienced situations in which a frightening experience has caused us to avoid places, people, and activities. But, is a fear-focused strategy one that health care providers should include in their quiver as we try to mold patient behavior? As luck would have it, 2 weeks before this news story broke I encountered a global study from 84 countries that sought to answer this question (Affect Sci. 2022 Sep. doi: 10.1007/s42761-022-00128-3).

Using the WHO four-point advice about COVID prevention (stay home/avoid shops/use face covering/isolate if exposed) as a model the researchers around the world reviewed the responses of 16,000 individuals. They found that there was no difference in the effectiveness of the message whether it was framed as a negative (“you have so much to lose”) or a positive (“you have so much to gain”). However, investigators observed that the negatively framed presentations generated significantly more anxiety in the respondents. The authors of the paper conclude that if there is no significant difference in the effectiveness, why would we chose a negatively framed presentation that is likely to generate anxiety that we know is associated with increased morbidity and mortality. From a purely public health perspective, it doesn’t make sense and is counterproductive.

I guess if we look back to the old carrot and stick metaphor we shouldn’t be surprised by the findings in this paper. If one’s only goal is to get a group of young preschoolers to behave by scaring the b’geezes out of them with a mask or a threat of bodily punishment, then go for it. Scare tactics will probably work just as well as offering a well-chosen reward system. However, the devil is in the side effects. It’s the same argument that I give to parents who argue that spanking works. Of course it does, but it has a narrow margin for safety and can set up ripples of negative side effects that can destroy healthy parent-child relationships.

The bottom line of this story is the sad truth that somewhere along the line someone failed to effectively train these four daycare workers. But, do we as health care providers need to rethink our training? Have we forgotten our commitment to “First do no harm?” As we craft our messaging have we thought enough about the potential side effects of our attempts at scaring the public into following our suggestions?

Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Other than a Littman stethoscope he accepted as a first-year medical student in 1966, Dr. Wilkoff reports having nothing to disclose. Email him at [email protected].

Perineuriomas are benign, slow-growing tumors derived from perineurial cells,¹ which form the structurally supportive perineurium that surrounds individual nerve fascicles.^2,3 Perineuriomas are classified into 2 main forms: intraneural or extraneural.⁴ Intraneural perineuriomas are found within the border of the peripheral nerve,⁵ while extraneural perineuriomas usually are found in soft tissue and skin. Extraneural perineuriomas can be further classified into variants based on their histologic appearance, including reticular, sclerosing, and plexiform subtypes. Extraneural perineuriomas usually present on the extremities or trunk of young to middle-aged adults as a well-circumscribed, painless, subcutaneous masses.¹ These tumors are especially unusual in children.⁴ We present 2 extraneural perineurioma cases in children, and we review the pertinent diagnostic features of perineurioma as well as the presentation in the pediatric population.

Case Reports

Patient 1—A 10-year-old boy with a history of cerebral palsy and related comorbidities presented to the clinic for evaluation of a lesion on the thigh with no associated pain, irritation, erythema, or drainage. Physical examination revealed a soft, pedunculated, mobile nodule on the right medial thigh. An elliptical excision was performed. Gross examination demonstrated a 2.0×2.0×1.8-cm polypoid nodule. Histologic examination showed a dermal-based proliferation of bland spindle cells (Figure 1). The cytomorphology was characterized by elongated tapering nuclei and many areas with delicate bipolar cytoplasmic processes. The constituent cells were arranged in a whorled pattern in a variably myxoid to collagenous stroma. The tumor cells were multifocally positive for CD34; focally positive for smooth muscle actin (SMA); and negative for S-100, epithelial membrane antigen (EMA), GLUT1, claudin-1, STAT6, and desmin. Rb protein was intact. The CD34 immunostain highlighted the cytoplasmic processes. Electron microscopy was performed because the immunohistochemical results were nonspecific despite the favorable histologic features for perineurioma and showed pinocytic vesicles with delicate cytoplasmic processes, characteristic of perineurioma (Figure 2). Follow-up visits were related to the management of multiple comorbidities; no known recurrence of the lesion was documented.

Patient 2—A 15-year-old adolescent boy with no notable medical history presented to the pediatric clinic for a bump on the right upper arm of 4 to 5 months’ duration. He did not recall an injury to the area and denied change in size, redness, bruising, or pain of the lesion. Ultrasonography demonstrated a 2.6×2.3×1.3-cm hypoechoic and slightly heterogeneous, well-circumscribed, subcutaneous mass with internal vascularity. The patient was then referred to a pediatric surgeon. The clinical differential included a lipoma, lymphadenopathy, or sebaceous cyst. An excision was performed. Gross inspection demonstrated a 7-g, 2.8×2.6×1.8-cm, homogeneous, tan-pink, rubbery nodule with minimal surrounding soft tissue. Histologic examination showed a bland proliferation of spindle cells with storiform and whorled patterns (Figure 3). No notable nuclear atypia or necrosis was identified. The tumor cells were focally positive for EMA (Figure 4), claudin-1, and CD34 and negative for S-100, SOX10, GLUT1, desmin, STAT6, pankeratin AE1/AE3, and SMA. The diagnosis of perineurioma was rendered. No recurrence of the lesion was appreciated clinically on a 6-month follow-up examination.

Comment

Characteristics of Perineuriomas—On gross evaluation, perineuriomas are firm, gray-white, and well circumscribed but not encapsulated. Histologically, perineuriomas can have a storiform, whorled, or lamellar pattern of spindle cells. Perivascular whorls can be a histologic clue. The spindle cells are bland appearing and typically are elongated and slender but can appear slightly ovoid and plump. The background stroma can be myxoid, collagenous, or mixed. There usually is no atypia, and mitotic figures are rare.^2,3,6,7 Intraneural perineuriomas vary architecturally in that they display a unique onion bulb–like appearance in which whorls of cytoplasmic material of variable sizes surround central axons.³

Diagnosis—The diagnosis of perineuriomas usually requires characteristic immunohistochemical and sometimes ultrastructural features. Perineuriomas are positive for EMA and GLUT1 and variable for CD34.⁶ Approximately 20% to 91% will be positive for claudin-1, a tight junction protein associated with perineuriomas.⁸ Of note, EMA and GLUT1 usually are positive in both neoplastic and nonneoplastic perineurial cells.^9,10 Occasionally, these tumors can be focally positive for SMA and negative for S-100 and glial fibrillary acidic protein. The bipolar, thin, delicate, cytoplasmic processes with long-tapering nuclei may be easier to appreciate on electron microscopy than on conventional light microscopy. In addition, the cells contain pinocytotic vesicles and a discontinuous external lamina, which may be helpful for diagnosis.¹⁰

Genetics—Genetic alterations in perineurioma continue to be elucidated. Although many soft tissue perineuriomas possess deletion of chromosome 22q material, this is not a consistent finding and is not pathognomonic. Notably, the NF2 tumor suppressor gene is found on chromosome 22.¹¹ For the sclerosing variant of perineurioma, rearrangements or deletions of chromosome 10q have been described. A study of 14 soft tissue/extraneural perineuriomas using whole-exome sequencing and single nucleotide polymorphism array showed 6 cases of recurrent chromosome 22q deletions containing the NF2 locus and 4 cases with a previously unreported finding of chromosome 17q deletions containing the NF1 locus that were mutually exclusive events in all but 1 case.¹² Although perineuriomas can harbor NF1 or NF2 mutations, perineuriomas are not considered to be associated with neurofibromatosis type 1 or 2 (NF1 or NF2, respectively). Patients with NF1 or NF2 and perineurioma are exceedingly rare. One pediatric patient with both soft tissue perineurioma and NF1 has been reported in the literature.¹³

Differential Diagnosis—Perineuriomas should be distinguished from other benign neural neoplasms of the skin and soft tissue. Commonly considered in the differential diagnosis is schwannoma and neurofibroma. Schwannomas are encapsulated epineurial nerve sheath tumors comprised of a neoplastic proliferation of Schwann cells. Schwannomas morphologically differ from perineuriomas because of the presence of the hypercellular Antoni A with Verocay bodies and the hypocellular myxoid Antoni B patterns of spindle cells with elongated wavy nuclei and tapered ends. Other features include hyalinized vessels, hemosiderin deposition, cystic degeneration, and/or degenerative atypia.^3,14 Importantly, the constituent cells of schwannomas are positive for S-100 and SOX10 and negative for EMA.³ Neurofibromas consist of fascicles and whorls of Schwann cells in a background myxoid stroma with scattered mast cells, lymphocytes, fibroblasts, and perineurial cells. Similar to schwannomas, neurofibromas also are positive for S-100 and negative for EMA.^3,14 Neurofibromas can have either a somatic or germline mutation of the biallelic NF1 gene on chromosome 17q11.2 with subsequent loss of protein neurofibromin activity.¹⁵ Less common but still a consideration are the hybrid peripheral nerve sheath tumors that may present with a biphasic or intermingled morphology. Combinations include neurofibroma-schwannoma, schwannoma-perineurioma, and neurofibroma-perineurioma. The hybrid schwannoma-perineurioma has a mixture of thin and plump spindle cells with tapered nuclei as well as patchy S-100 positivity corresponding to schwannian areas. Similarly, S-100 will highlight the wavy Schwann cells in neurofibroma-perineurioma as well as CD34-highlighting fibroblasts.^7,15 In both aforementioned hybrid tumors, EMA will be positive in the perineurial areas. Another potential diagnostic consideration that can occur in both pediatric and adult populations is dermatofibrosarcoma protuberans (DFSP), which is comprised of a dermal proliferation of monomorphic fusiform spindle cells. Although both perineuriomas and DFSP can have a storiform architecture, DFSP is more asymmetric and infiltrative. Dermatofibrosarcoma protuberans is recognized in areas of individual adipocyte trapping, referred to as honeycombing. Dermatofibrosarcoma protuberans typically does not express EMA, though the sclerosing variant of DFSP has been reported to sometimes demonstrate focal EMA reactivity.^11,14,16 For morphologically challenging cases, cytogenetic studies will show t(17;22) translocation fusing the COL1A1 and PDGFRB genes.¹⁶ Finally, for subcutaneous or deep-seated tumors, one also may consider other mesenchymal neoplasms, including solitary fibrous tumor, low-grade fibromyxoid sarcoma, or low-grade malignant peripheral nerve sheath tumor (MPNST).¹¹

Management—Perineuriomas are considered benign. The presence of mitotic figures, pleomorphism, and degenerative nuclear atypia akin to ancient change, as seen in ancient schwannoma, does not affect their benign clinical behavior. Treatment of a perineurioma typically is surgical excision with conservative margins and minimal chance of recurrence.^1,11 So-called malignant perineuriomas are better classified as MPNSTs with perineural differentiation or perineurial MPNST. They also are positive for EMA and may be distinguished from perineurioma by the presence of major atypia and an infiltrative growth pattern.^17,18

Considerations in the Pediatric Population—Few pediatric soft tissue perineuriomas have been reported. A clinicopathologic analysis by Hornick and Fletcher¹ of patients with soft tissue perineurioma showed that only 6 of 81 patients were younger than 20 years. The youngest reported case of perineurioma occurred as an extraneural perineurioma on the scalp in an infant.¹⁹ Only 1 soft tissue perineural MPNST has been reported in the pediatric population, arising on the face of an 11-year-old boy. In a case series of 11 pediatric perineuriomas, including extraneural and intraneural, there was no evidence of recurrence or metastasis at follow-up.⁴

Conclusion

Perineuriomas are rare benign peripheral nerve sheath tumors with unique histologic and immunohistochemical features. Soft tissue perineuriomas in the pediatric population are an important diagnostic consideration, especially for the pediatrician or dermatologist when encountering a well-circumscribed nodular soft tissue lesion of the extremity or when encountering a neural-appearing tumor in the subcutaneous tissue.

Acknowledgment—We would like to thank Christopher Fletcher, MD (Boston, Massachusetts), for his expertise in outside consultation for patient 1.

Perineuriomas are benign, slow-growing tumors derived from perineurial cells,¹ which form the structurally supportive perineurium that surrounds individual nerve fascicles.^2,3 Perineuriomas are classified into 2 main forms: intraneural or extraneural.⁴ Intraneural perineuriomas are found within the border of the peripheral nerve,⁵ while extraneural perineuriomas usually are found in soft tissue and skin. Extraneural perineuriomas can be further classified into variants based on their histologic appearance, including reticular, sclerosing, and plexiform subtypes. Extraneural perineuriomas usually present on the extremities or trunk of young to middle-aged adults as a well-circumscribed, painless, subcutaneous masses.¹ These tumors are especially unusual in children.⁴ We present 2 extraneural perineurioma cases in children, and we review the pertinent diagnostic features of perineurioma as well as the presentation in the pediatric population.

Case Reports

Patient 1—A 10-year-old boy with a history of cerebral palsy and related comorbidities presented to the clinic for evaluation of a lesion on the thigh with no associated pain, irritation, erythema, or drainage. Physical examination revealed a soft, pedunculated, mobile nodule on the right medial thigh. An elliptical excision was performed. Gross examination demonstrated a 2.0×2.0×1.8-cm polypoid nodule. Histologic examination showed a dermal-based proliferation of bland spindle cells (Figure 1). The cytomorphology was characterized by elongated tapering nuclei and many areas with delicate bipolar cytoplasmic processes. The constituent cells were arranged in a whorled pattern in a variably myxoid to collagenous stroma. The tumor cells were multifocally positive for CD34; focally positive for smooth muscle actin (SMA); and negative for S-100, epithelial membrane antigen (EMA), GLUT1, claudin-1, STAT6, and desmin. Rb protein was intact. The CD34 immunostain highlighted the cytoplasmic processes. Electron microscopy was performed because the immunohistochemical results were nonspecific despite the favorable histologic features for perineurioma and showed pinocytic vesicles with delicate cytoplasmic processes, characteristic of perineurioma (Figure 2). Follow-up visits were related to the management of multiple comorbidities; no known recurrence of the lesion was documented.

Patient 2—A 15-year-old adolescent boy with no notable medical history presented to the pediatric clinic for a bump on the right upper arm of 4 to 5 months’ duration. He did not recall an injury to the area and denied change in size, redness, bruising, or pain of the lesion. Ultrasonography demonstrated a 2.6×2.3×1.3-cm hypoechoic and slightly heterogeneous, well-circumscribed, subcutaneous mass with internal vascularity. The patient was then referred to a pediatric surgeon. The clinical differential included a lipoma, lymphadenopathy, or sebaceous cyst. An excision was performed. Gross inspection demonstrated a 7-g, 2.8×2.6×1.8-cm, homogeneous, tan-pink, rubbery nodule with minimal surrounding soft tissue. Histologic examination showed a bland proliferation of spindle cells with storiform and whorled patterns (Figure 3). No notable nuclear atypia or necrosis was identified. The tumor cells were focally positive for EMA (Figure 4), claudin-1, and CD34 and negative for S-100, SOX10, GLUT1, desmin, STAT6, pankeratin AE1/AE3, and SMA. The diagnosis of perineurioma was rendered. No recurrence of the lesion was appreciated clinically on a 6-month follow-up examination.

Comment

Characteristics of Perineuriomas—On gross evaluation, perineuriomas are firm, gray-white, and well circumscribed but not encapsulated. Histologically, perineuriomas can have a storiform, whorled, or lamellar pattern of spindle cells. Perivascular whorls can be a histologic clue. The spindle cells are bland appearing and typically are elongated and slender but can appear slightly ovoid and plump. The background stroma can be myxoid, collagenous, or mixed. There usually is no atypia, and mitotic figures are rare.^2,3,6,7 Intraneural perineuriomas vary architecturally in that they display a unique onion bulb–like appearance in which whorls of cytoplasmic material of variable sizes surround central axons.³

Diagnosis—The diagnosis of perineuriomas usually requires characteristic immunohistochemical and sometimes ultrastructural features. Perineuriomas are positive for EMA and GLUT1 and variable for CD34.⁶ Approximately 20% to 91% will be positive for claudin-1, a tight junction protein associated with perineuriomas.⁸ Of note, EMA and GLUT1 usually are positive in both neoplastic and nonneoplastic perineurial cells.^9,10 Occasionally, these tumors can be focally positive for SMA and negative for S-100 and glial fibrillary acidic protein. The bipolar, thin, delicate, cytoplasmic processes with long-tapering nuclei may be easier to appreciate on electron microscopy than on conventional light microscopy. In addition, the cells contain pinocytotic vesicles and a discontinuous external lamina, which may be helpful for diagnosis.¹⁰

Genetics—Genetic alterations in perineurioma continue to be elucidated. Although many soft tissue perineuriomas possess deletion of chromosome 22q material, this is not a consistent finding and is not pathognomonic. Notably, the NF2 tumor suppressor gene is found on chromosome 22.¹¹ For the sclerosing variant of perineurioma, rearrangements or deletions of chromosome 10q have been described. A study of 14 soft tissue/extraneural perineuriomas using whole-exome sequencing and single nucleotide polymorphism array showed 6 cases of recurrent chromosome 22q deletions containing the NF2 locus and 4 cases with a previously unreported finding of chromosome 17q deletions containing the NF1 locus that were mutually exclusive events in all but 1 case.¹² Although perineuriomas can harbor NF1 or NF2 mutations, perineuriomas are not considered to be associated with neurofibromatosis type 1 or 2 (NF1 or NF2, respectively). Patients with NF1 or NF2 and perineurioma are exceedingly rare. One pediatric patient with both soft tissue perineurioma and NF1 has been reported in the literature.¹³

Differential Diagnosis—Perineuriomas should be distinguished from other benign neural neoplasms of the skin and soft tissue. Commonly considered in the differential diagnosis is schwannoma and neurofibroma. Schwannomas are encapsulated epineurial nerve sheath tumors comprised of a neoplastic proliferation of Schwann cells. Schwannomas morphologically differ from perineuriomas because of the presence of the hypercellular Antoni A with Verocay bodies and the hypocellular myxoid Antoni B patterns of spindle cells with elongated wavy nuclei and tapered ends. Other features include hyalinized vessels, hemosiderin deposition, cystic degeneration, and/or degenerative atypia.^3,14 Importantly, the constituent cells of schwannomas are positive for S-100 and SOX10 and negative for EMA.³ Neurofibromas consist of fascicles and whorls of Schwann cells in a background myxoid stroma with scattered mast cells, lymphocytes, fibroblasts, and perineurial cells. Similar to schwannomas, neurofibromas also are positive for S-100 and negative for EMA.^3,14 Neurofibromas can have either a somatic or germline mutation of the biallelic NF1 gene on chromosome 17q11.2 with subsequent loss of protein neurofibromin activity.¹⁵ Less common but still a consideration are the hybrid peripheral nerve sheath tumors that may present with a biphasic or intermingled morphology. Combinations include neurofibroma-schwannoma, schwannoma-perineurioma, and neurofibroma-perineurioma. The hybrid schwannoma-perineurioma has a mixture of thin and plump spindle cells with tapered nuclei as well as patchy S-100 positivity corresponding to schwannian areas. Similarly, S-100 will highlight the wavy Schwann cells in neurofibroma-perineurioma as well as CD34-highlighting fibroblasts.^7,15 In both aforementioned hybrid tumors, EMA will be positive in the perineurial areas. Another potential diagnostic consideration that can occur in both pediatric and adult populations is dermatofibrosarcoma protuberans (DFSP), which is comprised of a dermal proliferation of monomorphic fusiform spindle cells. Although both perineuriomas and DFSP can have a storiform architecture, DFSP is more asymmetric and infiltrative. Dermatofibrosarcoma protuberans is recognized in areas of individual adipocyte trapping, referred to as honeycombing. Dermatofibrosarcoma protuberans typically does not express EMA, though the sclerosing variant of DFSP has been reported to sometimes demonstrate focal EMA reactivity.^11,14,16 For morphologically challenging cases, cytogenetic studies will show t(17;22) translocation fusing the COL1A1 and PDGFRB genes.¹⁶ Finally, for subcutaneous or deep-seated tumors, one also may consider other mesenchymal neoplasms, including solitary fibrous tumor, low-grade fibromyxoid sarcoma, or low-grade malignant peripheral nerve sheath tumor (MPNST).¹¹

Management—Perineuriomas are considered benign. The presence of mitotic figures, pleomorphism, and degenerative nuclear atypia akin to ancient change, as seen in ancient schwannoma, does not affect their benign clinical behavior. Treatment of a perineurioma typically is surgical excision with conservative margins and minimal chance of recurrence.^1,11 So-called malignant perineuriomas are better classified as MPNSTs with perineural differentiation or perineurial MPNST. They also are positive for EMA and may be distinguished from perineurioma by the presence of major atypia and an infiltrative growth pattern.^17,18

Considerations in the Pediatric Population—Few pediatric soft tissue perineuriomas have been reported. A clinicopathologic analysis by Hornick and Fletcher¹ of patients with soft tissue perineurioma showed that only 6 of 81 patients were younger than 20 years. The youngest reported case of perineurioma occurred as an extraneural perineurioma on the scalp in an infant.¹⁹ Only 1 soft tissue perineural MPNST has been reported in the pediatric population, arising on the face of an 11-year-old boy. In a case series of 11 pediatric perineuriomas, including extraneural and intraneural, there was no evidence of recurrence or metastasis at follow-up.⁴

Conclusion

Perineuriomas are rare benign peripheral nerve sheath tumors with unique histologic and immunohistochemical features. Soft tissue perineuriomas in the pediatric population are an important diagnostic consideration, especially for the pediatrician or dermatologist when encountering a well-circumscribed nodular soft tissue lesion of the extremity or when encountering a neural-appearing tumor in the subcutaneous tissue.

Acknowledgment—We would like to thank Christopher Fletcher, MD (Boston, Massachusetts), for his expertise in outside consultation for patient 1.

Perineuriomas are benign, slow-growing tumors derived from perineurial cells,¹ which form the structurally supportive perineurium that surrounds individual nerve fascicles.^2,3 Perineuriomas are classified into 2 main forms: intraneural or extraneural.⁴ Intraneural perineuriomas are found within the border of the peripheral nerve,⁵ while extraneural perineuriomas usually are found in soft tissue and skin. Extraneural perineuriomas can be further classified into variants based on their histologic appearance, including reticular, sclerosing, and plexiform subtypes. Extraneural perineuriomas usually present on the extremities or trunk of young to middle-aged adults as a well-circumscribed, painless, subcutaneous masses.¹ These tumors are especially unusual in children.⁴ We present 2 extraneural perineurioma cases in children, and we review the pertinent diagnostic features of perineurioma as well as the presentation in the pediatric population.

Case Reports

Patient 1—A 10-year-old boy with a history of cerebral palsy and related comorbidities presented to the clinic for evaluation of a lesion on the thigh with no associated pain, irritation, erythema, or drainage. Physical examination revealed a soft, pedunculated, mobile nodule on the right medial thigh. An elliptical excision was performed. Gross examination demonstrated a 2.0×2.0×1.8-cm polypoid nodule. Histologic examination showed a dermal-based proliferation of bland spindle cells (Figure 1). The cytomorphology was characterized by elongated tapering nuclei and many areas with delicate bipolar cytoplasmic processes. The constituent cells were arranged in a whorled pattern in a variably myxoid to collagenous stroma. The tumor cells were multifocally positive for CD34; focally positive for smooth muscle actin (SMA); and negative for S-100, epithelial membrane antigen (EMA), GLUT1, claudin-1, STAT6, and desmin. Rb protein was intact. The CD34 immunostain highlighted the cytoplasmic processes. Electron microscopy was performed because the immunohistochemical results were nonspecific despite the favorable histologic features for perineurioma and showed pinocytic vesicles with delicate cytoplasmic processes, characteristic of perineurioma (Figure 2). Follow-up visits were related to the management of multiple comorbidities; no known recurrence of the lesion was documented.

Patient 2—A 15-year-old adolescent boy with no notable medical history presented to the pediatric clinic for a bump on the right upper arm of 4 to 5 months’ duration. He did not recall an injury to the area and denied change in size, redness, bruising, or pain of the lesion. Ultrasonography demonstrated a 2.6×2.3×1.3-cm hypoechoic and slightly heterogeneous, well-circumscribed, subcutaneous mass with internal vascularity. The patient was then referred to a pediatric surgeon. The clinical differential included a lipoma, lymphadenopathy, or sebaceous cyst. An excision was performed. Gross inspection demonstrated a 7-g, 2.8×2.6×1.8-cm, homogeneous, tan-pink, rubbery nodule with minimal surrounding soft tissue. Histologic examination showed a bland proliferation of spindle cells with storiform and whorled patterns (Figure 3). No notable nuclear atypia or necrosis was identified. The tumor cells were focally positive for EMA (Figure 4), claudin-1, and CD34 and negative for S-100, SOX10, GLUT1, desmin, STAT6, pankeratin AE1/AE3, and SMA. The diagnosis of perineurioma was rendered. No recurrence of the lesion was appreciated clinically on a 6-month follow-up examination.

Comment

Characteristics of Perineuriomas—On gross evaluation, perineuriomas are firm, gray-white, and well circumscribed but not encapsulated. Histologically, perineuriomas can have a storiform, whorled, or lamellar pattern of spindle cells. Perivascular whorls can be a histologic clue. The spindle cells are bland appearing and typically are elongated and slender but can appear slightly ovoid and plump. The background stroma can be myxoid, collagenous, or mixed. There usually is no atypia, and mitotic figures are rare.^2,3,6,7 Intraneural perineuriomas vary architecturally in that they display a unique onion bulb–like appearance in which whorls of cytoplasmic material of variable sizes surround central axons.³

Diagnosis—The diagnosis of perineuriomas usually requires characteristic immunohistochemical and sometimes ultrastructural features. Perineuriomas are positive for EMA and GLUT1 and variable for CD34.⁶ Approximately 20% to 91% will be positive for claudin-1, a tight junction protein associated with perineuriomas.⁸ Of note, EMA and GLUT1 usually are positive in both neoplastic and nonneoplastic perineurial cells.^9,10 Occasionally, these tumors can be focally positive for SMA and negative for S-100 and glial fibrillary acidic protein. The bipolar, thin, delicate, cytoplasmic processes with long-tapering nuclei may be easier to appreciate on electron microscopy than on conventional light microscopy. In addition, the cells contain pinocytotic vesicles and a discontinuous external lamina, which may be helpful for diagnosis.¹⁰

Genetics—Genetic alterations in perineurioma continue to be elucidated. Although many soft tissue perineuriomas possess deletion of chromosome 22q material, this is not a consistent finding and is not pathognomonic. Notably, the NF2 tumor suppressor gene is found on chromosome 22.¹¹ For the sclerosing variant of perineurioma, rearrangements or deletions of chromosome 10q have been described. A study of 14 soft tissue/extraneural perineuriomas using whole-exome sequencing and single nucleotide polymorphism array showed 6 cases of recurrent chromosome 22q deletions containing the NF2 locus and 4 cases with a previously unreported finding of chromosome 17q deletions containing the NF1 locus that were mutually exclusive events in all but 1 case.¹² Although perineuriomas can harbor NF1 or NF2 mutations, perineuriomas are not considered to be associated with neurofibromatosis type 1 or 2 (NF1 or NF2, respectively). Patients with NF1 or NF2 and perineurioma are exceedingly rare. One pediatric patient with both soft tissue perineurioma and NF1 has been reported in the literature.¹³

Differential Diagnosis—Perineuriomas should be distinguished from other benign neural neoplasms of the skin and soft tissue. Commonly considered in the differential diagnosis is schwannoma and neurofibroma. Schwannomas are encapsulated epineurial nerve sheath tumors comprised of a neoplastic proliferation of Schwann cells. Schwannomas morphologically differ from perineuriomas because of the presence of the hypercellular Antoni A with Verocay bodies and the hypocellular myxoid Antoni B patterns of spindle cells with elongated wavy nuclei and tapered ends. Other features include hyalinized vessels, hemosiderin deposition, cystic degeneration, and/or degenerative atypia.^3,14 Importantly, the constituent cells of schwannomas are positive for S-100 and SOX10 and negative for EMA.³ Neurofibromas consist of fascicles and whorls of Schwann cells in a background myxoid stroma with scattered mast cells, lymphocytes, fibroblasts, and perineurial cells. Similar to schwannomas, neurofibromas also are positive for S-100 and negative for EMA.^3,14 Neurofibromas can have either a somatic or germline mutation of the biallelic NF1 gene on chromosome 17q11.2 with subsequent loss of protein neurofibromin activity.¹⁵ Less common but still a consideration are the hybrid peripheral nerve sheath tumors that may present with a biphasic or intermingled morphology. Combinations include neurofibroma-schwannoma, schwannoma-perineurioma, and neurofibroma-perineurioma. The hybrid schwannoma-perineurioma has a mixture of thin and plump spindle cells with tapered nuclei as well as patchy S-100 positivity corresponding to schwannian areas. Similarly, S-100 will highlight the wavy Schwann cells in neurofibroma-perineurioma as well as CD34-highlighting fibroblasts.^7,15 In both aforementioned hybrid tumors, EMA will be positive in the perineurial areas. Another potential diagnostic consideration that can occur in both pediatric and adult populations is dermatofibrosarcoma protuberans (DFSP), which is comprised of a dermal proliferation of monomorphic fusiform spindle cells. Although both perineuriomas and DFSP can have a storiform architecture, DFSP is more asymmetric and infiltrative. Dermatofibrosarcoma protuberans is recognized in areas of individual adipocyte trapping, referred to as honeycombing. Dermatofibrosarcoma protuberans typically does not express EMA, though the sclerosing variant of DFSP has been reported to sometimes demonstrate focal EMA reactivity.^11,14,16 For morphologically challenging cases, cytogenetic studies will show t(17;22) translocation fusing the COL1A1 and PDGFRB genes.¹⁶ Finally, for subcutaneous or deep-seated tumors, one also may consider other mesenchymal neoplasms, including solitary fibrous tumor, low-grade fibromyxoid sarcoma, or low-grade malignant peripheral nerve sheath tumor (MPNST).¹¹

Management—Perineuriomas are considered benign. The presence of mitotic figures, pleomorphism, and degenerative nuclear atypia akin to ancient change, as seen in ancient schwannoma, does not affect their benign clinical behavior. Treatment of a perineurioma typically is surgical excision with conservative margins and minimal chance of recurrence.^1,11 So-called malignant perineuriomas are better classified as MPNSTs with perineural differentiation or perineurial MPNST. They also are positive for EMA and may be distinguished from perineurioma by the presence of major atypia and an infiltrative growth pattern.^17,18

Considerations in the Pediatric Population—Few pediatric soft tissue perineuriomas have been reported. A clinicopathologic analysis by Hornick and Fletcher¹ of patients with soft tissue perineurioma showed that only 6 of 81 patients were younger than 20 years. The youngest reported case of perineurioma occurred as an extraneural perineurioma on the scalp in an infant.¹⁹ Only 1 soft tissue perineural MPNST has been reported in the pediatric population, arising on the face of an 11-year-old boy. In a case series of 11 pediatric perineuriomas, including extraneural and intraneural, there was no evidence of recurrence or metastasis at follow-up.⁴

Conclusion

Perineuriomas are rare benign peripheral nerve sheath tumors with unique histologic and immunohistochemical features. Soft tissue perineuriomas in the pediatric population are an important diagnostic consideration, especially for the pediatrician or dermatologist when encountering a well-circumscribed nodular soft tissue lesion of the extremity or when encountering a neural-appearing tumor in the subcutaneous tissue.

Acknowledgment—We would like to thank Christopher Fletcher, MD (Boston, Massachusetts), for his expertise in outside consultation for patient 1.

Atopic dermatitis (AD), or eczema, is a common inflammatory skin disease notorious for its chronic, relapsing, and often frustrating disease course. Although as many as 25% of children in the United States are affected by this condition and its impact on the quality of life of affected patients and families is profound,^1-3 therapeutic advances in the pediatric population have been fairly limited until recently.

Over the last 10 years, there has been robust investigation into pediatric AD therapeutics, with many topical and systemic medications either recently approved or under clinical investigation. These developments are changing the landscape of the management of pediatric AD and raise a set of fascinating questions about how early and aggressive intervention might change the course of this disease. We discuss current limitations in the field that may be addressed with additional research.

New Topical Medications

In the last several years, there has been a rapid increase in efforts to develop new topical agents to manage AD. Until the beginning of the 21st century, the dermatologist’s arsenal was limited to topical corticosteroids (TCs). In the early 2000s, attention shifted to topical calcineurin inhibitors as nonsteroidal alternatives when the US Food and Drug Administration (FDA) approved topical tacrolimus and pimecrolimus for AD. In 2016, crisaborole (a phosphodiesterase-4 [PDE4] inhibitor) was approved by the FDA for use in mild to moderate AD in patients 2 years and older, marking a new age of development for topical AD therapies. In 2021, the FDA approved ruxolitinib (a topical Janus kinase [JAK] 1/2 inhibitor) for use in mild to moderate AD in patients 12 years and older.

Roflumilast (ARQ-151) and difamilast (OPA-15406)(members of the PDE4 inhibitor class) are undergoing investigation for pediatric AD. A phase 3 clinical trial for roflumilast for AD is underway (ClinicalTrial.gov Identifier: NCT04845620); it is already approved for psoriasis in patients 12 years and older. A phase 3 trial of difamilast (NCT03911401) was recently completed, with results supporting the drug’s safety and efficacy in AD management.⁴ Efforts to synthesize new better-targeted PDE4 inhibitors are ongoing.⁵

Tapinarof (a novel aryl hydrocarbon receptor-modulating agent) is approved for psoriasis in adults, and a phase 3 trial for management of pediatric AD is underway (NCT05032859) after phase 2 trials revealed promising results.⁶

Lastly, the microbiome is a target for AD topical therapies. A recently completed phase 1 trial of bacteriotherapy with Staphylococcus hominis A9 transplant lotion showed promising results (NCT03151148).⁷ Although this bacteriotherapy technique is early in development and has been studied only in adult patients, results are exciting because they represent a gateway to a largely unexplored realm of potential future therapies.

Standard of Care—How will these new topical therapies impact our standard of care for pediatric AD patients? Topical corticosteroids are still a pillar of topical AD therapy, but the potential for nonsteroidal topical agents as alternatives and used in combination therapeutic regimens has expanded exponentially. It is uncertain how we might individualize regimens tailored to patient-specific factors because the standard approach has been to test drugs as monotherapy, with vehicle comparisons or with reference medications in Europe.

Newer topical nonsteroidal agents may offer several opportunities. First, they may help avoid local and systemic adverse effects that often limit the use of current standard therapy.⁸ This capability may prove essential in bridging TC treatments and serving as long-term maintenance therapies to decrease the frequency of eczema flares. Second, they can alleviate the need for different medication strengths for different body regions, thereby allowing for simplification of regimens and potentially increased adherence and decreased disease burden—a boon to affected patients and caregivers.

Although the efficacy and long-term safety profile of these new drugs require further study, it does not seem unreasonable to look forward to achieving levels of optimization and individualization with topical regimens for AD in the near future that makes flares in patients with mild to moderate AD a phenomenon of the past.

Advances in Systemic Therapy

Systemic therapeutics in pediatric AD also recently entered an exciting era of development. Traditional systemic agents, including cyclosporine, methotrexate, azathioprine, and mycophenolate mofetil, have existed for decades but have not been widely utilized for moderate to severe AD in the United States, especially in the pediatric population, likely because these drugs lacked FDA approval and they can cause a range of adverse effects, including notable immunosuppression.⁹

Introduction and approval of dupilumab in 2017 by the FDA was revolutionary in this field. As a monoclonal antibody targeted against IL-4 and IL-13, dupilumab has consistently demonstrated strong long-term efficacy for pediatric AD and has an acceptable safety profile in children and adolescents.^10-14 Expansion of the label to include children as young as 6 months with moderate to severe AD seems an important milestone in pediatric AD care.

Since the approval of dupilumab for adolescents and children aged 6 to 12 years, global experience has supported expanded use of systemic agents for patients who have an inadequate response to TCs and previously approved nonsteroidal topical agents. How expansive the use of systemics will be in younger children depends on how their long-term use impacts the disease course, whether therapy is disease modifying, and whether early use can curb the development of comorbidities.

Investigations into targeted systemic therapeutics for eczematous dermatitis are not limited to dupilumab. In a study of adolescents as young as 12 years, tralokinumab (an IL-13 pathway inhibitor) demonstrated an Eczema Area Severity Index-75 of 27.8% to 28.6% and a mean decrease in the SCORing Atopic Dermatitis index of 27.5 to 29.1, with minimal adverse effects.¹⁵ Lebrikizumab, another biologic IL-13 inhibitor with strong published safety and efficacy data in adults, has completed short- and longer-term studies in adolescents (NCT04178967 and NCT04146363).¹⁶ The drug received FDA Fast Track designation for moderate to severe AD in patients 12 years and older after showing positive data.¹⁷

This push to targeted therapy stretches beyond monoclonal antibodies. In the last few years, oral JAK inhibitors have emerged as a new class of systemic therapy for eczematous dermatitis. Upadacitinib, a JAK1 selective inhibitor, was approved by the FDA in 2022 for patients 12 years and older with AD and has data that supports its efficacy in adolescents and adults.¹⁸ Other JAK inhibitors including the selective JAK1 inhibitor abrocitinib and the combined JAK1/2 inhibitor baricitinib are being studied for pediatric AD (NCT04564755, NCT03422822, and NCT03952559), with most evidence to date supporting their safety and efficacy, at least over the short-term.¹⁹

The study of these and other advanced systemic therapies for eczematous dermatitis is transforming the toolbox for pediatric AD care. Although long-term data are lacking for some of these medications, it is possible that newer agents may decrease reliance on older immunosuppressants, such as systemic corticosteroids, cyclosporine, and methotrexate. Unanswered questions include: How and which systemic medications may alter the course of the disease? What is the disease modification for AD? What is the impact on comorbidities over time?

What’s Missing?

The field of pediatric AD has experienced exciting new developments with the emergence of targeted therapeutics, but those new agents require more long-term study, though we already have longer-term data on crisaborole and dupilumab.^10-14,20 Studies of the long-term use of these new treatments on comorbidities of pediatric AD—mental health outcomes, cardiovascular disease, effects on the family, and other allergic conditions—are needed.²¹ Furthermore, clinical guidelines that address indications, timing of use, tapering, and discontinuation of new treatments depend on long-term experience and data collection.

Therefore, it is prudent that investigators, companies, payers, patients, and families support phase 4, long-term extension, and registry studies, which will expand our knowledge of AD medications and their impact on the disease over time.

Final Thoughts

Medications to treat AD are reaching a new level of advancement—from topical agents that target novel pathways to revolutionary biologics and systemic medications. Although there are knowledge gaps on these new therapeutics, the standard of care is already rapidly changing as the expectations of clinicians, patients, and families advance with each addition to the provider’s toolbox.

Atopic dermatitis (AD), or eczema, is a common inflammatory skin disease notorious for its chronic, relapsing, and often frustrating disease course. Although as many as 25% of children in the United States are affected by this condition and its impact on the quality of life of affected patients and families is profound,^1-3 therapeutic advances in the pediatric population have been fairly limited until recently.

Over the last 10 years, there has been robust investigation into pediatric AD therapeutics, with many topical and systemic medications either recently approved or under clinical investigation. These developments are changing the landscape of the management of pediatric AD and raise a set of fascinating questions about how early and aggressive intervention might change the course of this disease. We discuss current limitations in the field that may be addressed with additional research.

New Topical Medications

In the last several years, there has been a rapid increase in efforts to develop new topical agents to manage AD. Until the beginning of the 21st century, the dermatologist’s arsenal was limited to topical corticosteroids (TCs). In the early 2000s, attention shifted to topical calcineurin inhibitors as nonsteroidal alternatives when the US Food and Drug Administration (FDA) approved topical tacrolimus and pimecrolimus for AD. In 2016, crisaborole (a phosphodiesterase-4 [PDE4] inhibitor) was approved by the FDA for use in mild to moderate AD in patients 2 years and older, marking a new age of development for topical AD therapies. In 2021, the FDA approved ruxolitinib (a topical Janus kinase [JAK] 1/2 inhibitor) for use in mild to moderate AD in patients 12 years and older.

Roflumilast (ARQ-151) and difamilast (OPA-15406)(members of the PDE4 inhibitor class) are undergoing investigation for pediatric AD. A phase 3 clinical trial for roflumilast for AD is underway (ClinicalTrial.gov Identifier: NCT04845620); it is already approved for psoriasis in patients 12 years and older. A phase 3 trial of difamilast (NCT03911401) was recently completed, with results supporting the drug’s safety and efficacy in AD management.⁴ Efforts to synthesize new better-targeted PDE4 inhibitors are ongoing.⁵

Tapinarof (a novel aryl hydrocarbon receptor-modulating agent) is approved for psoriasis in adults, and a phase 3 trial for management of pediatric AD is underway (NCT05032859) after phase 2 trials revealed promising results.⁶

Lastly, the microbiome is a target for AD topical therapies. A recently completed phase 1 trial of bacteriotherapy with Staphylococcus hominis A9 transplant lotion showed promising results (NCT03151148).⁷ Although this bacteriotherapy technique is early in development and has been studied only in adult patients, results are exciting because they represent a gateway to a largely unexplored realm of potential future therapies.

Standard of Care—How will these new topical therapies impact our standard of care for pediatric AD patients? Topical corticosteroids are still a pillar of topical AD therapy, but the potential for nonsteroidal topical agents as alternatives and used in combination therapeutic regimens has expanded exponentially. It is uncertain how we might individualize regimens tailored to patient-specific factors because the standard approach has been to test drugs as monotherapy, with vehicle comparisons or with reference medications in Europe.

Newer topical nonsteroidal agents may offer several opportunities. First, they may help avoid local and systemic adverse effects that often limit the use of current standard therapy.⁸ This capability may prove essential in bridging TC treatments and serving as long-term maintenance therapies to decrease the frequency of eczema flares. Second, they can alleviate the need for different medication strengths for different body regions, thereby allowing for simplification of regimens and potentially increased adherence and decreased disease burden—a boon to affected patients and caregivers.

Although the efficacy and long-term safety profile of these new drugs require further study, it does not seem unreasonable to look forward to achieving levels of optimization and individualization with topical regimens for AD in the near future that makes flares in patients with mild to moderate AD a phenomenon of the past.

Advances in Systemic Therapy

Systemic therapeutics in pediatric AD also recently entered an exciting era of development. Traditional systemic agents, including cyclosporine, methotrexate, azathioprine, and mycophenolate mofetil, have existed for decades but have not been widely utilized for moderate to severe AD in the United States, especially in the pediatric population, likely because these drugs lacked FDA approval and they can cause a range of adverse effects, including notable immunosuppression.⁹

Introduction and approval of dupilumab in 2017 by the FDA was revolutionary in this field. As a monoclonal antibody targeted against IL-4 and IL-13, dupilumab has consistently demonstrated strong long-term efficacy for pediatric AD and has an acceptable safety profile in children and adolescents.^10-14 Expansion of the label to include children as young as 6 months with moderate to severe AD seems an important milestone in pediatric AD care.

Since the approval of dupilumab for adolescents and children aged 6 to 12 years, global experience has supported expanded use of systemic agents for patients who have an inadequate response to TCs and previously approved nonsteroidal topical agents. How expansive the use of systemics will be in younger children depends on how their long-term use impacts the disease course, whether therapy is disease modifying, and whether early use can curb the development of comorbidities.

Investigations into targeted systemic therapeutics for eczematous dermatitis are not limited to dupilumab. In a study of adolescents as young as 12 years, tralokinumab (an IL-13 pathway inhibitor) demonstrated an Eczema Area Severity Index-75 of 27.8% to 28.6% and a mean decrease in the SCORing Atopic Dermatitis index of 27.5 to 29.1, with minimal adverse effects.¹⁵ Lebrikizumab, another biologic IL-13 inhibitor with strong published safety and efficacy data in adults, has completed short- and longer-term studies in adolescents (NCT04178967 and NCT04146363).¹⁶ The drug received FDA Fast Track designation for moderate to severe AD in patients 12 years and older after showing positive data.¹⁷

This push to targeted therapy stretches beyond monoclonal antibodies. In the last few years, oral JAK inhibitors have emerged as a new class of systemic therapy for eczematous dermatitis. Upadacitinib, a JAK1 selective inhibitor, was approved by the FDA in 2022 for patients 12 years and older with AD and has data that supports its efficacy in adolescents and adults.¹⁸ Other JAK inhibitors including the selective JAK1 inhibitor abrocitinib and the combined JAK1/2 inhibitor baricitinib are being studied for pediatric AD (NCT04564755, NCT03422822, and NCT03952559), with most evidence to date supporting their safety and efficacy, at least over the short-term.¹⁹

The study of these and other advanced systemic therapies for eczematous dermatitis is transforming the toolbox for pediatric AD care. Although long-term data are lacking for some of these medications, it is possible that newer agents may decrease reliance on older immunosuppressants, such as systemic corticosteroids, cyclosporine, and methotrexate. Unanswered questions include: How and which systemic medications may alter the course of the disease? What is the disease modification for AD? What is the impact on comorbidities over time?

What’s Missing?

The field of pediatric AD has experienced exciting new developments with the emergence of targeted therapeutics, but those new agents require more long-term study, though we already have longer-term data on crisaborole and dupilumab.^10-14,20 Studies of the long-term use of these new treatments on comorbidities of pediatric AD—mental health outcomes, cardiovascular disease, effects on the family, and other allergic conditions—are needed.²¹ Furthermore, clinical guidelines that address indications, timing of use, tapering, and discontinuation of new treatments depend on long-term experience and data collection.

Therefore, it is prudent that investigators, companies, payers, patients, and families support phase 4, long-term extension, and registry studies, which will expand our knowledge of AD medications and their impact on the disease over time.

Final Thoughts

Medications to treat AD are reaching a new level of advancement—from topical agents that target novel pathways to revolutionary biologics and systemic medications. Although there are knowledge gaps on these new therapeutics, the standard of care is already rapidly changing as the expectations of clinicians, patients, and families advance with each addition to the provider’s toolbox.

Atopic dermatitis (AD), or eczema, is a common inflammatory skin disease notorious for its chronic, relapsing, and often frustrating disease course. Although as many as 25% of children in the United States are affected by this condition and its impact on the quality of life of affected patients and families is profound,^1-3 therapeutic advances in the pediatric population have been fairly limited until recently.

Over the last 10 years, there has been robust investigation into pediatric AD therapeutics, with many topical and systemic medications either recently approved or under clinical investigation. These developments are changing the landscape of the management of pediatric AD and raise a set of fascinating questions about how early and aggressive intervention might change the course of this disease. We discuss current limitations in the field that may be addressed with additional research.

New Topical Medications

In the last several years, there has been a rapid increase in efforts to develop new topical agents to manage AD. Until the beginning of the 21st century, the dermatologist’s arsenal was limited to topical corticosteroids (TCs). In the early 2000s, attention shifted to topical calcineurin inhibitors as nonsteroidal alternatives when the US Food and Drug Administration (FDA) approved topical tacrolimus and pimecrolimus for AD. In 2016, crisaborole (a phosphodiesterase-4 [PDE4] inhibitor) was approved by the FDA for use in mild to moderate AD in patients 2 years and older, marking a new age of development for topical AD therapies. In 2021, the FDA approved ruxolitinib (a topical Janus kinase [JAK] 1/2 inhibitor) for use in mild to moderate AD in patients 12 years and older.

Roflumilast (ARQ-151) and difamilast (OPA-15406)(members of the PDE4 inhibitor class) are undergoing investigation for pediatric AD. A phase 3 clinical trial for roflumilast for AD is underway (ClinicalTrial.gov Identifier: NCT04845620); it is already approved for psoriasis in patients 12 years and older. A phase 3 trial of difamilast (NCT03911401) was recently completed, with results supporting the drug’s safety and efficacy in AD management.⁴ Efforts to synthesize new better-targeted PDE4 inhibitors are ongoing.⁵

Tapinarof (a novel aryl hydrocarbon receptor-modulating agent) is approved for psoriasis in adults, and a phase 3 trial for management of pediatric AD is underway (NCT05032859) after phase 2 trials revealed promising results.⁶

Lastly, the microbiome is a target for AD topical therapies. A recently completed phase 1 trial of bacteriotherapy with Staphylococcus hominis A9 transplant lotion showed promising results (NCT03151148).⁷ Although this bacteriotherapy technique is early in development and has been studied only in adult patients, results are exciting because they represent a gateway to a largely unexplored realm of potential future therapies.

Standard of Care—How will these new topical therapies impact our standard of care for pediatric AD patients? Topical corticosteroids are still a pillar of topical AD therapy, but the potential for nonsteroidal topical agents as alternatives and used in combination therapeutic regimens has expanded exponentially. It is uncertain how we might individualize regimens tailored to patient-specific factors because the standard approach has been to test drugs as monotherapy, with vehicle comparisons or with reference medications in Europe.

Newer topical nonsteroidal agents may offer several opportunities. First, they may help avoid local and systemic adverse effects that often limit the use of current standard therapy.⁸ This capability may prove essential in bridging TC treatments and serving as long-term maintenance therapies to decrease the frequency of eczema flares. Second, they can alleviate the need for different medication strengths for different body regions, thereby allowing for simplification of regimens and potentially increased adherence and decreased disease burden—a boon to affected patients and caregivers.

Although the efficacy and long-term safety profile of these new drugs require further study, it does not seem unreasonable to look forward to achieving levels of optimization and individualization with topical regimens for AD in the near future that makes flares in patients with mild to moderate AD a phenomenon of the past.

Advances in Systemic Therapy

Systemic therapeutics in pediatric AD also recently entered an exciting era of development. Traditional systemic agents, including cyclosporine, methotrexate, azathioprine, and mycophenolate mofetil, have existed for decades but have not been widely utilized for moderate to severe AD in the United States, especially in the pediatric population, likely because these drugs lacked FDA approval and they can cause a range of adverse effects, including notable immunosuppression.⁹

Introduction and approval of dupilumab in 2017 by the FDA was revolutionary in this field. As a monoclonal antibody targeted against IL-4 and IL-13, dupilumab has consistently demonstrated strong long-term efficacy for pediatric AD and has an acceptable safety profile in children and adolescents.^10-14 Expansion of the label to include children as young as 6 months with moderate to severe AD seems an important milestone in pediatric AD care.

Since the approval of dupilumab for adolescents and children aged 6 to 12 years, global experience has supported expanded use of systemic agents for patients who have an inadequate response to TCs and previously approved nonsteroidal topical agents. How expansive the use of systemics will be in younger children depends on how their long-term use impacts the disease course, whether therapy is disease modifying, and whether early use can curb the development of comorbidities.

Investigations into targeted systemic therapeutics for eczematous dermatitis are not limited to dupilumab. In a study of adolescents as young as 12 years, tralokinumab (an IL-13 pathway inhibitor) demonstrated an Eczema Area Severity Index-75 of 27.8% to 28.6% and a mean decrease in the SCORing Atopic Dermatitis index of 27.5 to 29.1, with minimal adverse effects.¹⁵ Lebrikizumab, another biologic IL-13 inhibitor with strong published safety and efficacy data in adults, has completed short- and longer-term studies in adolescents (NCT04178967 and NCT04146363).¹⁶ The drug received FDA Fast Track designation for moderate to severe AD in patients 12 years and older after showing positive data.¹⁷

This push to targeted therapy stretches beyond monoclonal antibodies. In the last few years, oral JAK inhibitors have emerged as a new class of systemic therapy for eczematous dermatitis. Upadacitinib, a JAK1 selective inhibitor, was approved by the FDA in 2022 for patients 12 years and older with AD and has data that supports its efficacy in adolescents and adults.¹⁸ Other JAK inhibitors including the selective JAK1 inhibitor abrocitinib and the combined JAK1/2 inhibitor baricitinib are being studied for pediatric AD (NCT04564755, NCT03422822, and NCT03952559), with most evidence to date supporting their safety and efficacy, at least over the short-term.¹⁹

The study of these and other advanced systemic therapies for eczematous dermatitis is transforming the toolbox for pediatric AD care. Although long-term data are lacking for some of these medications, it is possible that newer agents may decrease reliance on older immunosuppressants, such as systemic corticosteroids, cyclosporine, and methotrexate. Unanswered questions include: How and which systemic medications may alter the course of the disease? What is the disease modification for AD? What is the impact on comorbidities over time?

What’s Missing?

The field of pediatric AD has experienced exciting new developments with the emergence of targeted therapeutics, but those new agents require more long-term study, though we already have longer-term data on crisaborole and dupilumab.^10-14,20 Studies of the long-term use of these new treatments on comorbidities of pediatric AD—mental health outcomes, cardiovascular disease, effects on the family, and other allergic conditions—are needed.²¹ Furthermore, clinical guidelines that address indications, timing of use, tapering, and discontinuation of new treatments depend on long-term experience and data collection.

Therefore, it is prudent that investigators, companies, payers, patients, and families support phase 4, long-term extension, and registry studies, which will expand our knowledge of AD medications and their impact on the disease over time.

Final Thoughts

Medications to treat AD are reaching a new level of advancement—from topical agents that target novel pathways to revolutionary biologics and systemic medications. Although there are knowledge gaps on these new therapeutics, the standard of care is already rapidly changing as the expectations of clinicians, patients, and families advance with each addition to the provider’s toolbox.

Acrodermatitis enteropathica (AE) is a rare disorder of zinc metabolism that typically presents in infancy.¹ Although it is clinically characterized by acral and periorificial dermatitis, alopecia, and diarrhea, only 20% of cases present with this triad.² Zinc deficiency in AE can either be acquired or inborn (congenital). Acquired forms can occur from dietary inadequacy or malabsorption, whereas genetic causes are related to an autosomal-recessive disorder affecting zinc transporters.¹ We report a case of a 3-month-old female infant with acquired AE who was successfully treated with zinc supplementation over the course of 3 weeks.

Case Report

A 3-month-old female infant presented to the emergency department with a rash of 2 weeks’ duration. She was born full term with no birth complications. The patient’s mother reported that the rash started on the cheeks, then enlarged and spread to the neck, back, and perineum. The patient also had been having diarrhea during this time. She previously had received mupirocin and cephalexin with no response to treatment. Maternal history was negative for lupus, and the mother’s diet consisted of a variety of foods but not many vegetables. The patient was exclusively breastfed, and there was no pertinent history of similar rashes occurring in other family members.

Physical examination revealed the patient had annular and polycyclic, hyperkeratotic, crusted papules and plaques on the cheeks, neck, back, and axillae, as well as the perineum/groin and perianal regions (Figure 1). The differential diagnosis at the time included neonatal lupus, zinc deficiency, and syphilis. Relevant laboratory testing and a shave biopsy of the left axilla were obtained.

Comment

Etiology of AE—Acrodermatitis enteropathica was first identified in 1942 as an acral rash associated with diarrhea³; in 1973, Barnes and Moynahan⁴ discovered zinc deficiency as a causal agent for these findings. The causes of AE are further subclassified as either an acquired or inborn etiology. Congenital causes commonly are seen in infants within the first few months of life, whereas acquired forms are seen at any age. Acquired forms in infants can occur from failure of the mother to secrete zinc in breast milk, low maternal serum zinc levels, or other reasons causing low nutritional intake. A single mutation in the SLC30A2 gene has been found to markedly reduce zinc concentrations in breast milk, thus causing zinc deficiency in breastfed infants.⁵ Other acquired forms can be caused by malabsorption, sometimes after surgery such as intestinal bypass or from intravenous nutrition without sufficient zinc.¹ The congenital form of AE is an autosomal-recessive disorder occurring from mutations in the SLC39A4 gene located on band 8q24.3. Affected individuals have a decreased ability to absorb zinc in the small intestine because of defects in zinc transporters ZIP and ZnT.⁶ Based on our patient’s laboratory findings and history, it is believed that the zinc deficiency was acquired, as the condition normalized with repletion and has not required any supplementation in the year of follow-up. In addition, the absence of a pertinent family history supported an acquired diagnosis, which has various etiologies, whereas the congenital form primarily is a genetic disease.

Diagnosis of AE—The characteristic clinical features of AE include erythematous, dry, scaly papules and plaques that may evolve into crusted, erosive, pustular lesions. These lesions typically are distributed in a periorificial and acral pattern.^1,2 Although AE includes the clinical triad of acral and periorificial dermatitis, alopecia, and diarrhea, most cases present with only partial features of this syndrome, as seen in our patient, who presented with only 2 symptoms—dermatitis and diarrhea. The diagnosis of AE is based on clinical and laboratory abnormalities, especially a low serum zinc level. Low levels of zinc-dependent enzymes, such as alkaline phosphatase, may support the diagnosis, as seen in our patient. Histologic evaluation is characteristic but is not diagnostic, as the same findings can be seen in other nutritional disorders. Such findings include confluent parakeratosis associated with a reduced granular layer in early lesions and subsequent ballooning of subcorneal keratinocytes, upper epidermal pallor, and intraepidermal clefts. Late lesions exhibit psoriasiform hyperplasia of the epidermis with less epidermal pallor.⁷

Acrodermatitis enteropathica (AE) is a rare disorder of zinc metabolism that typically presents in infancy.¹ Although it is clinically characterized by acral and periorificial dermatitis, alopecia, and diarrhea, only 20% of cases present with this triad.² Zinc deficiency in AE can either be acquired or inborn (congenital). Acquired forms can occur from dietary inadequacy or malabsorption, whereas genetic causes are related to an autosomal-recessive disorder affecting zinc transporters.¹ We report a case of a 3-month-old female infant with acquired AE who was successfully treated with zinc supplementation over the course of 3 weeks.

Case Report

A 3-month-old female infant presented to the emergency department with a rash of 2 weeks’ duration. She was born full term with no birth complications. The patient’s mother reported that the rash started on the cheeks, then enlarged and spread to the neck, back, and perineum. The patient also had been having diarrhea during this time. She previously had received mupirocin and cephalexin with no response to treatment. Maternal history was negative for lupus, and the mother’s diet consisted of a variety of foods but not many vegetables. The patient was exclusively breastfed, and there was no pertinent history of similar rashes occurring in other family members.

Physical examination revealed the patient had annular and polycyclic, hyperkeratotic, crusted papules and plaques on the cheeks, neck, back, and axillae, as well as the perineum/groin and perianal regions (Figure 1). The differential diagnosis at the time included neonatal lupus, zinc deficiency, and syphilis. Relevant laboratory testing and a shave biopsy of the left axilla were obtained.

Comment

Etiology of AE—Acrodermatitis enteropathica was first identified in 1942 as an acral rash associated with diarrhea³; in 1973, Barnes and Moynahan⁴ discovered zinc deficiency as a causal agent for these findings. The causes of AE are further subclassified as either an acquired or inborn etiology. Congenital causes commonly are seen in infants within the first few months of life, whereas acquired forms are seen at any age. Acquired forms in infants can occur from failure of the mother to secrete zinc in breast milk, low maternal serum zinc levels, or other reasons causing low nutritional intake. A single mutation in the SLC30A2 gene has been found to markedly reduce zinc concentrations in breast milk, thus causing zinc deficiency in breastfed infants.⁵ Other acquired forms can be caused by malabsorption, sometimes after surgery such as intestinal bypass or from intravenous nutrition without sufficient zinc.¹ The congenital form of AE is an autosomal-recessive disorder occurring from mutations in the SLC39A4 gene located on band 8q24.3. Affected individuals have a decreased ability to absorb zinc in the small intestine because of defects in zinc transporters ZIP and ZnT.⁶ Based on our patient’s laboratory findings and history, it is believed that the zinc deficiency was acquired, as the condition normalized with repletion and has not required any supplementation in the year of follow-up. In addition, the absence of a pertinent family history supported an acquired diagnosis, which has various etiologies, whereas the congenital form primarily is a genetic disease.

Diagnosis of AE—The characteristic clinical features of AE include erythematous, dry, scaly papules and plaques that may evolve into crusted, erosive, pustular lesions. These lesions typically are distributed in a periorificial and acral pattern.^1,2 Although AE includes the clinical triad of acral and periorificial dermatitis, alopecia, and diarrhea, most cases present with only partial features of this syndrome, as seen in our patient, who presented with only 2 symptoms—dermatitis and diarrhea. The diagnosis of AE is based on clinical and laboratory abnormalities, especially a low serum zinc level. Low levels of zinc-dependent enzymes, such as alkaline phosphatase, may support the diagnosis, as seen in our patient. Histologic evaluation is characteristic but is not diagnostic, as the same findings can be seen in other nutritional disorders. Such findings include confluent parakeratosis associated with a reduced granular layer in early lesions and subsequent ballooning of subcorneal keratinocytes, upper epidermal pallor, and intraepidermal clefts. Late lesions exhibit psoriasiform hyperplasia of the epidermis with less epidermal pallor.⁷

Acrodermatitis enteropathica (AE) is a rare disorder of zinc metabolism that typically presents in infancy.¹ Although it is clinically characterized by acral and periorificial dermatitis, alopecia, and diarrhea, only 20% of cases present with this triad.² Zinc deficiency in AE can either be acquired or inborn (congenital). Acquired forms can occur from dietary inadequacy or malabsorption, whereas genetic causes are related to an autosomal-recessive disorder affecting zinc transporters.¹ We report a case of a 3-month-old female infant with acquired AE who was successfully treated with zinc supplementation over the course of 3 weeks.

Case Report

A 3-month-old female infant presented to the emergency department with a rash of 2 weeks’ duration. She was born full term with no birth complications. The patient’s mother reported that the rash started on the cheeks, then enlarged and spread to the neck, back, and perineum. The patient also had been having diarrhea during this time. She previously had received mupirocin and cephalexin with no response to treatment. Maternal history was negative for lupus, and the mother’s diet consisted of a variety of foods but not many vegetables. The patient was exclusively breastfed, and there was no pertinent history of similar rashes occurring in other family members.

Physical examination revealed the patient had annular and polycyclic, hyperkeratotic, crusted papules and plaques on the cheeks, neck, back, and axillae, as well as the perineum/groin and perianal regions (Figure 1). The differential diagnosis at the time included neonatal lupus, zinc deficiency, and syphilis. Relevant laboratory testing and a shave biopsy of the left axilla were obtained.

Comment

Etiology of AE—Acrodermatitis enteropathica was first identified in 1942 as an acral rash associated with diarrhea³; in 1973, Barnes and Moynahan⁴ discovered zinc deficiency as a causal agent for these findings. The causes of AE are further subclassified as either an acquired or inborn etiology. Congenital causes commonly are seen in infants within the first few months of life, whereas acquired forms are seen at any age. Acquired forms in infants can occur from failure of the mother to secrete zinc in breast milk, low maternal serum zinc levels, or other reasons causing low nutritional intake. A single mutation in the SLC30A2 gene has been found to markedly reduce zinc concentrations in breast milk, thus causing zinc deficiency in breastfed infants.⁵ Other acquired forms can be caused by malabsorption, sometimes after surgery such as intestinal bypass or from intravenous nutrition without sufficient zinc.¹ The congenital form of AE is an autosomal-recessive disorder occurring from mutations in the SLC39A4 gene located on band 8q24.3. Affected individuals have a decreased ability to absorb zinc in the small intestine because of defects in zinc transporters ZIP and ZnT.⁶ Based on our patient’s laboratory findings and history, it is believed that the zinc deficiency was acquired, as the condition normalized with repletion and has not required any supplementation in the year of follow-up. In addition, the absence of a pertinent family history supported an acquired diagnosis, which has various etiologies, whereas the congenital form primarily is a genetic disease.

Diagnosis of AE—The characteristic clinical features of AE include erythematous, dry, scaly papules and plaques that may evolve into crusted, erosive, pustular lesions. These lesions typically are distributed in a periorificial and acral pattern.^1,2 Although AE includes the clinical triad of acral and periorificial dermatitis, alopecia, and diarrhea, most cases present with only partial features of this syndrome, as seen in our patient, who presented with only 2 symptoms—dermatitis and diarrhea. The diagnosis of AE is based on clinical and laboratory abnormalities, especially a low serum zinc level. Low levels of zinc-dependent enzymes, such as alkaline phosphatase, may support the diagnosis, as seen in our patient. Histologic evaluation is characteristic but is not diagnostic, as the same findings can be seen in other nutritional disorders. Such findings include confluent parakeratosis associated with a reduced granular layer in early lesions and subsequent ballooning of subcorneal keratinocytes, upper epidermal pallor, and intraepidermal clefts. Late lesions exhibit psoriasiform hyperplasia of the epidermis with less epidermal pallor.⁷

Photoallergic contact dermatitis (PACD), a subtype of allergic contact dermatitis that occurs because of the specific combination of exposure to an exogenous chemical applied topically to the skin and UV radiation, may be more common than was once thought.¹ Although the incidence in the general population is unknown, current research points to approximately 20% to 40% of patients with suspected photosensitivity having a PACD diagnosis.² Recently, the North American Contact Dermatitis Group (NACDG) reported that 21% of 373 patients undergoing photopatch testing (PPT) were diagnosed with PACD²; however, PPT is not routinely performed, which may contribute to underdiagnosis.

Mechanism of Disease

Similar to allergic contact dermatitis, PACD is a delayed type IV hypersensitivity reaction; however, it only occurs when an exogenous chemical is applied topically to the skin with concomitant exposure to UV radiation, usually in the UVA range (315–400 nm).^3,4 When exposed to UV radiation, it is thought that the exogenous chemical combines with a protein in the skin and transforms into a photoantigen. In the sensitization phase, the photoantigen is taken up by antigen-presenting cells in the epidermis and transported to local lymph nodes where antigen-specific T cells are generated.⁵ In the elicitation phase, the inflammatory reaction of PACD occurs upon subsequent exposure to the same chemical plus UV radiation.⁴ Development of PACD does not necessarily depend on the dose of the chemical or the amount of UV radiation.⁶ Why certain individuals may be more susceptible is unknown, though major histocompatibility complex haplotypes could be influential.^7,8

Clinical Manifestations

Photoallergic contact dermatitis primarily presents in sun-exposed areas of the skin (eg, face, neck, V area of the chest, dorsal upper extremities) with sparing of naturally photoprotected sites, such as the upper eyelids and nasolabial and retroauricular folds. Other than its characteristic photodistribution, PACD often is clinically indistinguishable from routine allergic contact dermatitis. It manifests as a pruritic, poorly demarcated, eczematous or sometimes vesiculobullous eruption that develops in a delayed fashion—24 to 72 hours after sun exposure. The dermatitis may extend to other parts of the body either through spread of the chemical agent by the hands or clothing or due to the systemic nature of the immune response. The severity of the presentation can vary depending on multiple factors, such as concentration and absorption of the agent, length of exposure, intensity and duration of UV radiation exposure, and individual susceptibility.⁴ Chronic PACD may become lichenified. Generally, rashes resolve after discontinuation of the causative agent; however, long-term exposure may lead to development of chronic actinic dermatitis, with persistent photodistributed eczema regardless of contact with the initial inciting agent.⁹

Differential Diagnosis

The differential diagnosis for patients presenting with photodistributed dermatitis is broad; therefore, taking a thorough history is important. Considerations include age of onset, timing and persistence of reactions, use of topical and systemic medications (both prescription and over-the-counter [OTC]), personal care products, occupation, and hobbies, as well as a thorough review of systems.

It is important to distinguish PACD from phototoxic contact dermatitis (PTCD)(also known as photoirritant contact dermatitis)(Table). Asking about the onset and timing of the eruption may be critical for distinction, as PTCD can occur within minutes to hours of the first exposure to a chemical and UV radiation, while there is a sensitization delay in PACD.⁶ Phytophotodermatitis is a well-known type of PTCD caused by exposure to furocoumarin-containing plants, most commonly limes.¹⁰ Other causes of PTCD include tar products and certain medications.¹¹ Importantly, PPT to a known phototoxic chemical should never be performed because it will cause a strong reaction in anyone tested, regardless of exposure history.

Diagnosis

Histologically, PACD presents similarly to allergic contact dermatitis with spongiotic dermatitis; therefore, biopsy cannot be relied upon to make the diagnosis.⁶ Photopatch testing is required for definitive diagnosis. It is reasonable to perform PPT in any patient with chronic dermatitis primarily affecting sun-exposed areas without a clear alternative diagnosis.^14,15 Of note, at present there are no North American consensus guidelines for PPT, but typically duplicate sets of photoallergens are applied to both sides of the patient’s back and one side is exposed to UVA radiation. The reactions are compared after 48 to 96 hours.¹⁵ A positive reaction only at the irradiated site is consistent with photoallergy, while a reaction of equal strength at both the irradiated and nonirradiated sites indicates regular contact allergy. The case of a reaction occurring at both sites with a stronger response at the irradiated site is known as photoaggravated contact allergy, which can be thought of as allergic contact dermatitis that worsens but does not solely occur with exposure to sunlight.

Although PPT is necessary for the accurate diagnosis of PACD, it is infrequently used. Two surveys of 112 and 117 American Contact Dermatitis Society members, respectively, have revealed that only around half performed PPT, most of them testing fewer than 20 times per year.^16,17 Additionally, there was variability in the test methodology and allergens employed. Nevertheless, most respondents tested sunscreens, nonsteroidal anti-inflammatory drugs (NSAIDs), fragrances, and their patients’ own products.^16,17 The most common reasons for not performing PPT were lack of equipment, insufficient skills, rare clinical suspicion, and cost. Dermatologists at academic centers performed more PPT than those in other practice settings, including multispecialty group practices and private offices.¹⁶ These findings highlight multiple factors that may contribute to reduced patient access to PPT and thus potential underdiagnosis of PACD.

Common Photoallergens

The most common photoallergens change over time in response to market trends; for example, fragrance was once a top photoallergen in the United States in the 1970s and 1980s but declined in prominence after musk ambrette—the primary allergen associated with PACD at the time—was removed as an ingredient in fragrances.¹⁸

In the largest and most recent PPT series from North America (1999-2009),² sunscreens comprised 7 of the top 10 most common photoallergens, which is consistent with other studies showing sunscreens to be the most common North American photoallergens.^19-22 The frequency of PACD due to sunscreens likely relates to their increasing use worldwide as awareness of photocarcinogenesis and photoaging grows, as well as the common use of UV filters in nonsunscreen personal care products, ranging from lip balms to perfumes and bodywashes. Chemical (organic) UV filters—in particular oxybenzone (benzophenone-3) and avobenzone (butyl methoxydibenzoylmethane)—are the most common sunscreen photoallergens.^2,23 Para-aminobenzoic acid was once a common photoallergen, but it is no longer used in US sunscreens due to safety concerns.^19,20 The physical (inorganic) UV filters zinc oxide and titanium dioxide are not known photosensitizers.

Methylisothiazolinone (MI) is a highly allergenic preservative commonly used in a wide array of personal care products, including sunscreens.²⁴ In the most recent NACDG patch test data, MI was the second most common contact allergen.²⁵ Allergic contact dermatitis caused by MI in sunscreen can mimic PACD.²⁶ In addition, MI can cause photoaggravated contact dermatitis, with some affected patients experiencing ongoing photosensitivity even after avoiding this allergen.^26-30 The European Union and Canada have introduced restrictions on the use of MI in personal care products, but no such regulatory measures have been taken in the United States to date.^25,31,32

After sunscreens, another common cause of PACD are topical NSAIDs, which are frequently used for musculoskeletal pain relief. These are of particular concern in Europe, where a variety of formulations are widely available OTC.³³ Ketoprofen and etofenamate are responsible for the largest number of PACD reactions in Europe.^2,34,35 Meanwhile, the only OTC topical NSAID available in the United States is diclofenac gel, which was approved in 2020. Cases of PACD due to use of diclofenac gel have been reported in the literature, but testing in larger populations is needed.^36-39

Notably, ketoprofen may co- or cross-react with certain UV filters—oxybenzone and octocrylene—and the lipid-lowering agent fenofibrate due to chemical similarities.^40-43 Despite the relatively high number of photoallergic reactions to ketoprofen in the NACDG photopatch series, only 25% (5/20) were considered clinically relevant (ie, the allergen could not be verified as present in the known skin contactants of the patient, and the patient was not exposed to circumstances in which contact with materials known to contain the allergen would likely occur), which suggests that they likely represented cross-reactions in patients sensitized to sunscreens.²

Other agents that may cause PACD include antimicrobials, plants and plant derivatives, and pesticides.^2,4,18 The antimicrobial fentichlor is a common cause of positive PPT reactions, but it rarely is clinically relevant.⁴⁴

Treatment

The primary management of PACD centers on identification of the causative photoallergen to avoid future exposure. Patients should be educated on the various names by which the causative allergen can be identified on product labels and should be given a list of safe products that are free from relevant allergens and cross-reacting chemicals.⁴⁵ Additionally, sun protection education should be provided. Exposure to UVA radiation can occur through windows, making the use of broad-spectrum sunscreens and protective clothing crucial. In cases of sunscreen-induced PACD, the responsible chemical UV filter(s) should be avoided, or alternatively, patients may use physical sunscreens containing only zinc oxide and/or titanium dioxide as active ingredients, as these are not known to cause PACD.⁴

When avoidance alone is insufficient, topical corticosteroids are the usual first-line treatment for localized PACD. When steroid-sparing treatments are preferred, topical calcineurin inhibitors such as tacrolimus and pimecrolimus may be used. If PACD is more widespread and severe, systemic therapy using steroids or steroid-sparing agents may be necessary to provide symptomatic relief.⁴

Final Interpretation

Photoallergic contact dermatitis is not uncommon, particularly among photosensitive patients. Most cases are due to sunscreens or topical NSAIDs. Consideration of PPT should be given in any patient with a chronic photodistributed dermatitis to evaluate for the possibility of PACD.

Photoallergic contact dermatitis (PACD), a subtype of allergic contact dermatitis that occurs because of the specific combination of exposure to an exogenous chemical applied topically to the skin and UV radiation, may be more common than was once thought.¹ Although the incidence in the general population is unknown, current research points to approximately 20% to 40% of patients with suspected photosensitivity having a PACD diagnosis.² Recently, the North American Contact Dermatitis Group (NACDG) reported that 21% of 373 patients undergoing photopatch testing (PPT) were diagnosed with PACD²; however, PPT is not routinely performed, which may contribute to underdiagnosis.

Mechanism of Disease

Similar to allergic contact dermatitis, PACD is a delayed type IV hypersensitivity reaction; however, it only occurs when an exogenous chemical is applied topically to the skin with concomitant exposure to UV radiation, usually in the UVA range (315–400 nm).^3,4 When exposed to UV radiation, it is thought that the exogenous chemical combines with a protein in the skin and transforms into a photoantigen. In the sensitization phase, the photoantigen is taken up by antigen-presenting cells in the epidermis and transported to local lymph nodes where antigen-specific T cells are generated.⁵ In the elicitation phase, the inflammatory reaction of PACD occurs upon subsequent exposure to the same chemical plus UV radiation.⁴ Development of PACD does not necessarily depend on the dose of the chemical or the amount of UV radiation.⁶ Why certain individuals may be more susceptible is unknown, though major histocompatibility complex haplotypes could be influential.^7,8

Clinical Manifestations

Photoallergic contact dermatitis primarily presents in sun-exposed areas of the skin (eg, face, neck, V area of the chest, dorsal upper extremities) with sparing of naturally photoprotected sites, such as the upper eyelids and nasolabial and retroauricular folds. Other than its characteristic photodistribution, PACD often is clinically indistinguishable from routine allergic contact dermatitis. It manifests as a pruritic, poorly demarcated, eczematous or sometimes vesiculobullous eruption that develops in a delayed fashion—24 to 72 hours after sun exposure. The dermatitis may extend to other parts of the body either through spread of the chemical agent by the hands or clothing or due to the systemic nature of the immune response. The severity of the presentation can vary depending on multiple factors, such as concentration and absorption of the agent, length of exposure, intensity and duration of UV radiation exposure, and individual susceptibility.⁴ Chronic PACD may become lichenified. Generally, rashes resolve after discontinuation of the causative agent; however, long-term exposure may lead to development of chronic actinic dermatitis, with persistent photodistributed eczema regardless of contact with the initial inciting agent.⁹

Differential Diagnosis

The differential diagnosis for patients presenting with photodistributed dermatitis is broad; therefore, taking a thorough history is important. Considerations include age of onset, timing and persistence of reactions, use of topical and systemic medications (both prescription and over-the-counter [OTC]), personal care products, occupation, and hobbies, as well as a thorough review of systems.

It is important to distinguish PACD from phototoxic contact dermatitis (PTCD)(also known as photoirritant contact dermatitis)(Table). Asking about the onset and timing of the eruption may be critical for distinction, as PTCD can occur within minutes to hours of the first exposure to a chemical and UV radiation, while there is a sensitization delay in PACD.⁶ Phytophotodermatitis is a well-known type of PTCD caused by exposure to furocoumarin-containing plants, most commonly limes.¹⁰ Other causes of PTCD include tar products and certain medications.¹¹ Importantly, PPT to a known phototoxic chemical should never be performed because it will cause a strong reaction in anyone tested, regardless of exposure history.

Diagnosis

Histologically, PACD presents similarly to allergic contact dermatitis with spongiotic dermatitis; therefore, biopsy cannot be relied upon to make the diagnosis.⁶ Photopatch testing is required for definitive diagnosis. It is reasonable to perform PPT in any patient with chronic dermatitis primarily affecting sun-exposed areas without a clear alternative diagnosis.^14,15 Of note, at present there are no North American consensus guidelines for PPT, but typically duplicate sets of photoallergens are applied to both sides of the patient’s back and one side is exposed to UVA radiation. The reactions are compared after 48 to 96 hours.¹⁵ A positive reaction only at the irradiated site is consistent with photoallergy, while a reaction of equal strength at both the irradiated and nonirradiated sites indicates regular contact allergy. The case of a reaction occurring at both sites with a stronger response at the irradiated site is known as photoaggravated contact allergy, which can be thought of as allergic contact dermatitis that worsens but does not solely occur with exposure to sunlight.

Although PPT is necessary for the accurate diagnosis of PACD, it is infrequently used. Two surveys of 112 and 117 American Contact Dermatitis Society members, respectively, have revealed that only around half performed PPT, most of them testing fewer than 20 times per year.^16,17 Additionally, there was variability in the test methodology and allergens employed. Nevertheless, most respondents tested sunscreens, nonsteroidal anti-inflammatory drugs (NSAIDs), fragrances, and their patients’ own products.^16,17 The most common reasons for not performing PPT were lack of equipment, insufficient skills, rare clinical suspicion, and cost. Dermatologists at academic centers performed more PPT than those in other practice settings, including multispecialty group practices and private offices.¹⁶ These findings highlight multiple factors that may contribute to reduced patient access to PPT and thus potential underdiagnosis of PACD.

Common Photoallergens

The most common photoallergens change over time in response to market trends; for example, fragrance was once a top photoallergen in the United States in the 1970s and 1980s but declined in prominence after musk ambrette—the primary allergen associated with PACD at the time—was removed as an ingredient in fragrances.¹⁸

In the largest and most recent PPT series from North America (1999-2009),² sunscreens comprised 7 of the top 10 most common photoallergens, which is consistent with other studies showing sunscreens to be the most common North American photoallergens.^19-22 The frequency of PACD due to sunscreens likely relates to their increasing use worldwide as awareness of photocarcinogenesis and photoaging grows, as well as the common use of UV filters in nonsunscreen personal care products, ranging from lip balms to perfumes and bodywashes. Chemical (organic) UV filters—in particular oxybenzone (benzophenone-3) and avobenzone (butyl methoxydibenzoylmethane)—are the most common sunscreen photoallergens.^2,23 Para-aminobenzoic acid was once a common photoallergen, but it is no longer used in US sunscreens due to safety concerns.^19,20 The physical (inorganic) UV filters zinc oxide and titanium dioxide are not known photosensitizers.

Methylisothiazolinone (MI) is a highly allergenic preservative commonly used in a wide array of personal care products, including sunscreens.²⁴ In the most recent NACDG patch test data, MI was the second most common contact allergen.²⁵ Allergic contact dermatitis caused by MI in sunscreen can mimic PACD.²⁶ In addition, MI can cause photoaggravated contact dermatitis, with some affected patients experiencing ongoing photosensitivity even after avoiding this allergen.^26-30 The European Union and Canada have introduced restrictions on the use of MI in personal care products, but no such regulatory measures have been taken in the United States to date.^25,31,32

After sunscreens, another common cause of PACD are topical NSAIDs, which are frequently used for musculoskeletal pain relief. These are of particular concern in Europe, where a variety of formulations are widely available OTC.³³ Ketoprofen and etofenamate are responsible for the largest number of PACD reactions in Europe.^2,34,35 Meanwhile, the only OTC topical NSAID available in the United States is diclofenac gel, which was approved in 2020. Cases of PACD due to use of diclofenac gel have been reported in the literature, but testing in larger populations is needed.^36-39

Notably, ketoprofen may co- or cross-react with certain UV filters—oxybenzone and octocrylene—and the lipid-lowering agent fenofibrate due to chemical similarities.^40-43 Despite the relatively high number of photoallergic reactions to ketoprofen in the NACDG photopatch series, only 25% (5/20) were considered clinically relevant (ie, the allergen could not be verified as present in the known skin contactants of the patient, and the patient was not exposed to circumstances in which contact with materials known to contain the allergen would likely occur), which suggests that they likely represented cross-reactions in patients sensitized to sunscreens.²

Other agents that may cause PACD include antimicrobials, plants and plant derivatives, and pesticides.^2,4,18 The antimicrobial fentichlor is a common cause of positive PPT reactions, but it rarely is clinically relevant.⁴⁴

Treatment

The primary management of PACD centers on identification of the causative photoallergen to avoid future exposure. Patients should be educated on the various names by which the causative allergen can be identified on product labels and should be given a list of safe products that are free from relevant allergens and cross-reacting chemicals.⁴⁵ Additionally, sun protection education should be provided. Exposure to UVA radiation can occur through windows, making the use of broad-spectrum sunscreens and protective clothing crucial. In cases of sunscreen-induced PACD, the responsible chemical UV filter(s) should be avoided, or alternatively, patients may use physical sunscreens containing only zinc oxide and/or titanium dioxide as active ingredients, as these are not known to cause PACD.⁴

When avoidance alone is insufficient, topical corticosteroids are the usual first-line treatment for localized PACD. When steroid-sparing treatments are preferred, topical calcineurin inhibitors such as tacrolimus and pimecrolimus may be used. If PACD is more widespread and severe, systemic therapy using steroids or steroid-sparing agents may be necessary to provide symptomatic relief.⁴

Final Interpretation

Photoallergic contact dermatitis is not uncommon, particularly among photosensitive patients. Most cases are due to sunscreens or topical NSAIDs. Consideration of PPT should be given in any patient with a chronic photodistributed dermatitis to evaluate for the possibility of PACD.

Photoallergic contact dermatitis (PACD), a subtype of allergic contact dermatitis that occurs because of the specific combination of exposure to an exogenous chemical applied topically to the skin and UV radiation, may be more common than was once thought.¹ Although the incidence in the general population is unknown, current research points to approximately 20% to 40% of patients with suspected photosensitivity having a PACD diagnosis.² Recently, the North American Contact Dermatitis Group (NACDG) reported that 21% of 373 patients undergoing photopatch testing (PPT) were diagnosed with PACD²; however, PPT is not routinely performed, which may contribute to underdiagnosis.

Mechanism of Disease

Similar to allergic contact dermatitis, PACD is a delayed type IV hypersensitivity reaction; however, it only occurs when an exogenous chemical is applied topically to the skin with concomitant exposure to UV radiation, usually in the UVA range (315–400 nm).^3,4 When exposed to UV radiation, it is thought that the exogenous chemical combines with a protein in the skin and transforms into a photoantigen. In the sensitization phase, the photoantigen is taken up by antigen-presenting cells in the epidermis and transported to local lymph nodes where antigen-specific T cells are generated.⁵ In the elicitation phase, the inflammatory reaction of PACD occurs upon subsequent exposure to the same chemical plus UV radiation.⁴ Development of PACD does not necessarily depend on the dose of the chemical or the amount of UV radiation.⁶ Why certain individuals may be more susceptible is unknown, though major histocompatibility complex haplotypes could be influential.^7,8

Clinical Manifestations

Photoallergic contact dermatitis primarily presents in sun-exposed areas of the skin (eg, face, neck, V area of the chest, dorsal upper extremities) with sparing of naturally photoprotected sites, such as the upper eyelids and nasolabial and retroauricular folds. Other than its characteristic photodistribution, PACD often is clinically indistinguishable from routine allergic contact dermatitis. It manifests as a pruritic, poorly demarcated, eczematous or sometimes vesiculobullous eruption that develops in a delayed fashion—24 to 72 hours after sun exposure. The dermatitis may extend to other parts of the body either through spread of the chemical agent by the hands or clothing or due to the systemic nature of the immune response. The severity of the presentation can vary depending on multiple factors, such as concentration and absorption of the agent, length of exposure, intensity and duration of UV radiation exposure, and individual susceptibility.⁴ Chronic PACD may become lichenified. Generally, rashes resolve after discontinuation of the causative agent; however, long-term exposure may lead to development of chronic actinic dermatitis, with persistent photodistributed eczema regardless of contact with the initial inciting agent.⁹

Differential Diagnosis

The differential diagnosis for patients presenting with photodistributed dermatitis is broad; therefore, taking a thorough history is important. Considerations include age of onset, timing and persistence of reactions, use of topical and systemic medications (both prescription and over-the-counter [OTC]), personal care products, occupation, and hobbies, as well as a thorough review of systems.

It is important to distinguish PACD from phototoxic contact dermatitis (PTCD)(also known as photoirritant contact dermatitis)(Table). Asking about the onset and timing of the eruption may be critical for distinction, as PTCD can occur within minutes to hours of the first exposure to a chemical and UV radiation, while there is a sensitization delay in PACD.⁶ Phytophotodermatitis is a well-known type of PTCD caused by exposure to furocoumarin-containing plants, most commonly limes.¹⁰ Other causes of PTCD include tar products and certain medications.¹¹ Importantly, PPT to a known phototoxic chemical should never be performed because it will cause a strong reaction in anyone tested, regardless of exposure history.

Diagnosis

Histologically, PACD presents similarly to allergic contact dermatitis with spongiotic dermatitis; therefore, biopsy cannot be relied upon to make the diagnosis.⁶ Photopatch testing is required for definitive diagnosis. It is reasonable to perform PPT in any patient with chronic dermatitis primarily affecting sun-exposed areas without a clear alternative diagnosis.^14,15 Of note, at present there are no North American consensus guidelines for PPT, but typically duplicate sets of photoallergens are applied to both sides of the patient’s back and one side is exposed to UVA radiation. The reactions are compared after 48 to 96 hours.¹⁵ A positive reaction only at the irradiated site is consistent with photoallergy, while a reaction of equal strength at both the irradiated and nonirradiated sites indicates regular contact allergy. The case of a reaction occurring at both sites with a stronger response at the irradiated site is known as photoaggravated contact allergy, which can be thought of as allergic contact dermatitis that worsens but does not solely occur with exposure to sunlight.

Although PPT is necessary for the accurate diagnosis of PACD, it is infrequently used. Two surveys of 112 and 117 American Contact Dermatitis Society members, respectively, have revealed that only around half performed PPT, most of them testing fewer than 20 times per year.^16,17 Additionally, there was variability in the test methodology and allergens employed. Nevertheless, most respondents tested sunscreens, nonsteroidal anti-inflammatory drugs (NSAIDs), fragrances, and their patients’ own products.^16,17 The most common reasons for not performing PPT were lack of equipment, insufficient skills, rare clinical suspicion, and cost. Dermatologists at academic centers performed more PPT than those in other practice settings, including multispecialty group practices and private offices.¹⁶ These findings highlight multiple factors that may contribute to reduced patient access to PPT and thus potential underdiagnosis of PACD.

Common Photoallergens

The most common photoallergens change over time in response to market trends; for example, fragrance was once a top photoallergen in the United States in the 1970s and 1980s but declined in prominence after musk ambrette—the primary allergen associated with PACD at the time—was removed as an ingredient in fragrances.¹⁸

In the largest and most recent PPT series from North America (1999-2009),² sunscreens comprised 7 of the top 10 most common photoallergens, which is consistent with other studies showing sunscreens to be the most common North American photoallergens.^19-22 The frequency of PACD due to sunscreens likely relates to their increasing use worldwide as awareness of photocarcinogenesis and photoaging grows, as well as the common use of UV filters in nonsunscreen personal care products, ranging from lip balms to perfumes and bodywashes. Chemical (organic) UV filters—in particular oxybenzone (benzophenone-3) and avobenzone (butyl methoxydibenzoylmethane)—are the most common sunscreen photoallergens.^2,23 Para-aminobenzoic acid was once a common photoallergen, but it is no longer used in US sunscreens due to safety concerns.^19,20 The physical (inorganic) UV filters zinc oxide and titanium dioxide are not known photosensitizers.

Methylisothiazolinone (MI) is a highly allergenic preservative commonly used in a wide array of personal care products, including sunscreens.²⁴ In the most recent NACDG patch test data, MI was the second most common contact allergen.²⁵ Allergic contact dermatitis caused by MI in sunscreen can mimic PACD.²⁶ In addition, MI can cause photoaggravated contact dermatitis, with some affected patients experiencing ongoing photosensitivity even after avoiding this allergen.^26-30 The European Union and Canada have introduced restrictions on the use of MI in personal care products, but no such regulatory measures have been taken in the United States to date.^25,31,32

After sunscreens, another common cause of PACD are topical NSAIDs, which are frequently used for musculoskeletal pain relief. These are of particular concern in Europe, where a variety of formulations are widely available OTC.³³ Ketoprofen and etofenamate are responsible for the largest number of PACD reactions in Europe.^2,34,35 Meanwhile, the only OTC topical NSAID available in the United States is diclofenac gel, which was approved in 2020. Cases of PACD due to use of diclofenac gel have been reported in the literature, but testing in larger populations is needed.^36-39

Notably, ketoprofen may co- or cross-react with certain UV filters—oxybenzone and octocrylene—and the lipid-lowering agent fenofibrate due to chemical similarities.^40-43 Despite the relatively high number of photoallergic reactions to ketoprofen in the NACDG photopatch series, only 25% (5/20) were considered clinically relevant (ie, the allergen could not be verified as present in the known skin contactants of the patient, and the patient was not exposed to circumstances in which contact with materials known to contain the allergen would likely occur), which suggests that they likely represented cross-reactions in patients sensitized to sunscreens.²

Other agents that may cause PACD include antimicrobials, plants and plant derivatives, and pesticides.^2,4,18 The antimicrobial fentichlor is a common cause of positive PPT reactions, but it rarely is clinically relevant.⁴⁴

Treatment

The primary management of PACD centers on identification of the causative photoallergen to avoid future exposure. Patients should be educated on the various names by which the causative allergen can be identified on product labels and should be given a list of safe products that are free from relevant allergens and cross-reacting chemicals.⁴⁵ Additionally, sun protection education should be provided. Exposure to UVA radiation can occur through windows, making the use of broad-spectrum sunscreens and protective clothing crucial. In cases of sunscreen-induced PACD, the responsible chemical UV filter(s) should be avoided, or alternatively, patients may use physical sunscreens containing only zinc oxide and/or titanium dioxide as active ingredients, as these are not known to cause PACD.⁴

When avoidance alone is insufficient, topical corticosteroids are the usual first-line treatment for localized PACD. When steroid-sparing treatments are preferred, topical calcineurin inhibitors such as tacrolimus and pimecrolimus may be used. If PACD is more widespread and severe, systemic therapy using steroids or steroid-sparing agents may be necessary to provide symptomatic relief.⁴

Final Interpretation

Photoallergic contact dermatitis is not uncommon, particularly among photosensitive patients. Most cases are due to sunscreens or topical NSAIDs. Consideration of PPT should be given in any patient with a chronic photodistributed dermatitis to evaluate for the possibility of PACD.

Tinea capitis (TC) most often is caused by Trichophyton tonsurans and Microsporum canis. The peak incidence is between 3 and 7 years of age. Noninflammatory TC typically presents as fine scaling with single or multiple scaly patches of circular alopecia (grey patches); diffuse or patchy, fine, white, adherent scaling of the scalp resembling generalized dandruff with subtle hair loss; or single or multiple patches of well-demarcated areas of alopecia with fine scale studded with broken-off hairs at the scalp surface, resulting in a black dot appearance. Inflammatory variants of TC include kerion and favus.¹ Herein, updates on diagnosis, treatment, and monitoring of TC are provided, as well as a discussion of changes in the fungal microbiome associated with TC. Lastly, insights to some queries that practitioners may encounter when treating children with TC are provided.

Genetic Susceptibility

Molecular techniques have identified a number of macrophage regulator, leukocyte activation and migration, and cutaneous permeability genes associated with susceptibility to TC. These findings indicate that genetically determined deficiency in adaptive immune responses may affect the predisposition to dermatophyte infections.²

Clinical Varieties of Infection

Dermatophytes causing ringworm are capable of invading the hair shafts and can simultaneously invade smooth or glabrous skin (eg, T tonsurans, Trichophyton schoenleinii, Trichophyton violaceum). Some causative dermatophytes can even penetrate the nails (eg, Trichophyton soudanense). The clinical presentation is dependent on 3 main patterns of hair invasion³:

• Ectothrix: A mid-follicular pattern of invasion with hyphae growing down to the hair bulb that commonly is caused by Microsporum species. It clinically presents with scaling and inflammation with hair shafts breaking 2 to 3 mm above the scalp level.

• Endothrix: This pattern is nonfluorescent on Wood lamp examination, and hairs often break at the scalp level (black dot type). Trichophyton tonsurans, T soudanense, Trichophyton rubrum, and T violaceum are common causes.

• Favus: In this pattern, T schoenleinii is a common cause, and hairs grow to considerable lengths above the scalp with less damage than the other patterns. The hair shafts present with characteristic air spaces, and hyphae form clusters at the level of the epidermis.

Diagnosis

Optimal treatment of TC relies on proper identification of the causative agent. Fungal culture remains the gold standard of mycologic diagnosis regardless of its delayed results, which may take up to 4 weeks for proper identification of the fungal colonies and require ample expertise to interpret the morphologic features of the grown colonies.⁴

Other tests such as the potassium hydroxide preparation are nonspecific and do not identify the dermatophyte species. Although this method has been reported to have 5% to 15% false-negative results in routine practice depending on the skill of the observer and the quality of sampling, microscopic examination is essential, as it may allow the clinician to start treatment sooner pending culture results. The use of a Wood lamp is not suitable for definitive species identification, as this technique primarily is useful for observing fluorescence in ectothrix infection caused by Microsporum species, with the exception of T schoenleinii; otherwise, Trichophyton species, which cause endothrix infections, do not fluoresce.⁵Polymerase chain reaction is a sensitive technique that can help identify both the genus and species of common dermatophytes. Common target sequences include the ribosomal internal transcribed spacer and translation elongation factor 1α. The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also has become popular for dermatophyte identification.⁶Trichoscopic diagnosis of TC, which is simple and noninvasive, is becoming increasingly popular. Features such as short, broken, black dot, comma, corkscrew, and/or zigzag hairs, as well as perifollicular scaling, are helpful for diagnosing TC (Figure). Moreover, trichoscopy can be useful for differentiating other common causes of hair loss, such as trichotillomania and alopecia areata. It had been reported that the trichoscopic features of TC can be seen as early as 2 weeks after starting treatment and therefore this can be a reliable period in which to follow-up with the patient to evaluate progress. The disappearance of black dots and comma hairs can be appreciated from 2 weeks onwards by trichoscopic evaluation.⁴

Treatment

The common recommendation for first-line treatment of TC is the use of systemic antifungals with the use of a topical agent as an adjuvant to prevent the spread of fungal spores. For almost 6 decades, griseofulvin had been the gold-standard fungistatic used for treating TC in patients older than 2 years until the 2007 US Food and Drug Administration (FDA) approval of terbinafine fungicidal oral granules for treatment of TC in patients older than 4 years.⁷

Meta-analyses have demonstrated comparable efficacy for a 4-week course of terbinafine compared to 6 weeks of griseofulvin for TC based on the infectious organism. Terbinafine demonstrated superiority in treating T tonsurans and a similar efficacy in treating T violaceum, while griseofulvin was superior in treating M canis and other Microsporum species.^8,9

The off-label use of fluconazole and itraconazole to treat TC is gaining popularity, with limited trials showing increased evidence of their effectiveness. There is not much clinical evidence to support the use of other oral antifungals, including the newer azoles such as voriconazole or posaconazole.⁹

Newer limited evidence has shown the off-label use of photodynamic therapy to be a promising alternative to systemic antifungal therapy in treating TC, pending validation by larger sample trials.¹⁰In my practice, I have found that severe cases of TC demonstrating inflammation or possible widespread id reactions are better treated with oral steroids. Ketoconazole shampoo or selenium sulfide used 2 to 3 times weekly to prevent spread in the early phases of therapy is a good adjunct to systemic treatment. Cases with kerions should be assessed for the possibility of a coexisting bacterial infection under the crusts, and if confirmed, antibiotics should be started.⁹The commonly used systemic antifungals generally are safe with a low side-effect profile, but there is a risk for hepatotoxicity. The FDA recommends that baseline alanine transaminase and aspartate transaminase levels should be obtained prior to beginning a terbinafine-based treatment regimen.¹¹ The American Academy of Pediatrics has specifically stated that laboratory testing of serum hepatic enzymes is not a requirement if a griseofulvin-based regimen does not exceed 8 weeks; however, transaminase levels (alanine transaminase and aspartate transaminase) should be considered in patients using terbinafine at baseline or if treatment is prolonged beyond 4 to 6 weeks.¹² In agreement with the FDA guidelines, the Canadian Pediatric Society has suggested that liver enzymes should be periodically monitored in patients being treated with terbinafine beyond 4 to 6 weeks.¹³

Changes in the Fungal Microbiome

Research has shown that changes in the fungal microbiome were associated with an altered bacterial community in patients with TC. During fungal infection, the relative abundances of Cutibacterium and Corynebacterium increased, and the relative abundance of Streptococcus decreased. In addition, some uncommon bacterial genera such as Herbaspirillum and Methylorubrum were detected on the scalp in TC.¹⁴

Carrier State

Carrier state is determined for those siblings and contacts of cases with a clinically normal scalp that are positive on culture. Those individuals could represent a potential reservoir responsible for contamination (or recontamination) of the patient as well as treatment failure. Opinions remain divided as to whether to use oral antifungal therapy in these carriers or maintain therapy on antifungal shampoos containing ketoconazole or povidone-iodine. Due to the paucity of available data, my experience has shown that it is sufficient to use antifungal shampoos for such carriers. In zoophilic infections, it is important to identify and treat the animal source.^6-9

Final Thoughts

Successful treatment of TC requires accurate identification of the pathogen, which commonly is achieved via fungal culture. Despite its practical value, the conventional identification of dermatophytes based on morphologic features can be highly challenging due to the low positive rate and delayed results. Trichoscopy is a quick, handy, and noninvasive tool that can better indicate the diagnosis and also is helpful for follow-up on treatment progress. Due to better understanding of the immunology and genetic susceptibility associated with TC spread, the current treatment pipeline holds more insight into better control of this condition. Increased surveillance, prompt diagnosis, and early onset of systemic treatment are the key to proper prevention of spread of TC.

Tinea capitis (TC) most often is caused by Trichophyton tonsurans and Microsporum canis. The peak incidence is between 3 and 7 years of age. Noninflammatory TC typically presents as fine scaling with single or multiple scaly patches of circular alopecia (grey patches); diffuse or patchy, fine, white, adherent scaling of the scalp resembling generalized dandruff with subtle hair loss; or single or multiple patches of well-demarcated areas of alopecia with fine scale studded with broken-off hairs at the scalp surface, resulting in a black dot appearance. Inflammatory variants of TC include kerion and favus.¹ Herein, updates on diagnosis, treatment, and monitoring of TC are provided, as well as a discussion of changes in the fungal microbiome associated with TC. Lastly, insights to some queries that practitioners may encounter when treating children with TC are provided.

Genetic Susceptibility

Molecular techniques have identified a number of macrophage regulator, leukocyte activation and migration, and cutaneous permeability genes associated with susceptibility to TC. These findings indicate that genetically determined deficiency in adaptive immune responses may affect the predisposition to dermatophyte infections.²

Clinical Varieties of Infection

Dermatophytes causing ringworm are capable of invading the hair shafts and can simultaneously invade smooth or glabrous skin (eg, T tonsurans, Trichophyton schoenleinii, Trichophyton violaceum). Some causative dermatophytes can even penetrate the nails (eg, Trichophyton soudanense). The clinical presentation is dependent on 3 main patterns of hair invasion³:

• Ectothrix: A mid-follicular pattern of invasion with hyphae growing down to the hair bulb that commonly is caused by Microsporum species. It clinically presents with scaling and inflammation with hair shafts breaking 2 to 3 mm above the scalp level.

• Endothrix: This pattern is nonfluorescent on Wood lamp examination, and hairs often break at the scalp level (black dot type). Trichophyton tonsurans, T soudanense, Trichophyton rubrum, and T violaceum are common causes.

• Favus: In this pattern, T schoenleinii is a common cause, and hairs grow to considerable lengths above the scalp with less damage than the other patterns. The hair shafts present with characteristic air spaces, and hyphae form clusters at the level of the epidermis.

Diagnosis

Optimal treatment of TC relies on proper identification of the causative agent. Fungal culture remains the gold standard of mycologic diagnosis regardless of its delayed results, which may take up to 4 weeks for proper identification of the fungal colonies and require ample expertise to interpret the morphologic features of the grown colonies.⁴

Other tests such as the potassium hydroxide preparation are nonspecific and do not identify the dermatophyte species. Although this method has been reported to have 5% to 15% false-negative results in routine practice depending on the skill of the observer and the quality of sampling, microscopic examination is essential, as it may allow the clinician to start treatment sooner pending culture results. The use of a Wood lamp is not suitable for definitive species identification, as this technique primarily is useful for observing fluorescence in ectothrix infection caused by Microsporum species, with the exception of T schoenleinii; otherwise, Trichophyton species, which cause endothrix infections, do not fluoresce.⁵Polymerase chain reaction is a sensitive technique that can help identify both the genus and species of common dermatophytes. Common target sequences include the ribosomal internal transcribed spacer and translation elongation factor 1α. The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also has become popular for dermatophyte identification.⁶Trichoscopic diagnosis of TC, which is simple and noninvasive, is becoming increasingly popular. Features such as short, broken, black dot, comma, corkscrew, and/or zigzag hairs, as well as perifollicular scaling, are helpful for diagnosing TC (Figure). Moreover, trichoscopy can be useful for differentiating other common causes of hair loss, such as trichotillomania and alopecia areata. It had been reported that the trichoscopic features of TC can be seen as early as 2 weeks after starting treatment and therefore this can be a reliable period in which to follow-up with the patient to evaluate progress. The disappearance of black dots and comma hairs can be appreciated from 2 weeks onwards by trichoscopic evaluation.⁴

Treatment

The common recommendation for first-line treatment of TC is the use of systemic antifungals with the use of a topical agent as an adjuvant to prevent the spread of fungal spores. For almost 6 decades, griseofulvin had been the gold-standard fungistatic used for treating TC in patients older than 2 years until the 2007 US Food and Drug Administration (FDA) approval of terbinafine fungicidal oral granules for treatment of TC in patients older than 4 years.⁷

Meta-analyses have demonstrated comparable efficacy for a 4-week course of terbinafine compared to 6 weeks of griseofulvin for TC based on the infectious organism. Terbinafine demonstrated superiority in treating T tonsurans and a similar efficacy in treating T violaceum, while griseofulvin was superior in treating M canis and other Microsporum species.^8,9

The off-label use of fluconazole and itraconazole to treat TC is gaining popularity, with limited trials showing increased evidence of their effectiveness. There is not much clinical evidence to support the use of other oral antifungals, including the newer azoles such as voriconazole or posaconazole.⁹

Newer limited evidence has shown the off-label use of photodynamic therapy to be a promising alternative to systemic antifungal therapy in treating TC, pending validation by larger sample trials.¹⁰In my practice, I have found that severe cases of TC demonstrating inflammation or possible widespread id reactions are better treated with oral steroids. Ketoconazole shampoo or selenium sulfide used 2 to 3 times weekly to prevent spread in the early phases of therapy is a good adjunct to systemic treatment. Cases with kerions should be assessed for the possibility of a coexisting bacterial infection under the crusts, and if confirmed, antibiotics should be started.⁹The commonly used systemic antifungals generally are safe with a low side-effect profile, but there is a risk for hepatotoxicity. The FDA recommends that baseline alanine transaminase and aspartate transaminase levels should be obtained prior to beginning a terbinafine-based treatment regimen.¹¹ The American Academy of Pediatrics has specifically stated that laboratory testing of serum hepatic enzymes is not a requirement if a griseofulvin-based regimen does not exceed 8 weeks; however, transaminase levels (alanine transaminase and aspartate transaminase) should be considered in patients using terbinafine at baseline or if treatment is prolonged beyond 4 to 6 weeks.¹² In agreement with the FDA guidelines, the Canadian Pediatric Society has suggested that liver enzymes should be periodically monitored in patients being treated with terbinafine beyond 4 to 6 weeks.¹³

Changes in the Fungal Microbiome

Research has shown that changes in the fungal microbiome were associated with an altered bacterial community in patients with TC. During fungal infection, the relative abundances of Cutibacterium and Corynebacterium increased, and the relative abundance of Streptococcus decreased. In addition, some uncommon bacterial genera such as Herbaspirillum and Methylorubrum were detected on the scalp in TC.¹⁴

Carrier State

Carrier state is determined for those siblings and contacts of cases with a clinically normal scalp that are positive on culture. Those individuals could represent a potential reservoir responsible for contamination (or recontamination) of the patient as well as treatment failure. Opinions remain divided as to whether to use oral antifungal therapy in these carriers or maintain therapy on antifungal shampoos containing ketoconazole or povidone-iodine. Due to the paucity of available data, my experience has shown that it is sufficient to use antifungal shampoos for such carriers. In zoophilic infections, it is important to identify and treat the animal source.^6-9

Final Thoughts

Successful treatment of TC requires accurate identification of the pathogen, which commonly is achieved via fungal culture. Despite its practical value, the conventional identification of dermatophytes based on morphologic features can be highly challenging due to the low positive rate and delayed results. Trichoscopy is a quick, handy, and noninvasive tool that can better indicate the diagnosis and also is helpful for follow-up on treatment progress. Due to better understanding of the immunology and genetic susceptibility associated with TC spread, the current treatment pipeline holds more insight into better control of this condition. Increased surveillance, prompt diagnosis, and early onset of systemic treatment are the key to proper prevention of spread of TC.

Tinea capitis (TC) most often is caused by Trichophyton tonsurans and Microsporum canis. The peak incidence is between 3 and 7 years of age. Noninflammatory TC typically presents as fine scaling with single or multiple scaly patches of circular alopecia (grey patches); diffuse or patchy, fine, white, adherent scaling of the scalp resembling generalized dandruff with subtle hair loss; or single or multiple patches of well-demarcated areas of alopecia with fine scale studded with broken-off hairs at the scalp surface, resulting in a black dot appearance. Inflammatory variants of TC include kerion and favus.¹ Herein, updates on diagnosis, treatment, and monitoring of TC are provided, as well as a discussion of changes in the fungal microbiome associated with TC. Lastly, insights to some queries that practitioners may encounter when treating children with TC are provided.

Genetic Susceptibility

Molecular techniques have identified a number of macrophage regulator, leukocyte activation and migration, and cutaneous permeability genes associated with susceptibility to TC. These findings indicate that genetically determined deficiency in adaptive immune responses may affect the predisposition to dermatophyte infections.²

Clinical Varieties of Infection

Dermatophytes causing ringworm are capable of invading the hair shafts and can simultaneously invade smooth or glabrous skin (eg, T tonsurans, Trichophyton schoenleinii, Trichophyton violaceum). Some causative dermatophytes can even penetrate the nails (eg, Trichophyton soudanense). The clinical presentation is dependent on 3 main patterns of hair invasion³:

• Ectothrix: A mid-follicular pattern of invasion with hyphae growing down to the hair bulb that commonly is caused by Microsporum species. It clinically presents with scaling and inflammation with hair shafts breaking 2 to 3 mm above the scalp level.

• Endothrix: This pattern is nonfluorescent on Wood lamp examination, and hairs often break at the scalp level (black dot type). Trichophyton tonsurans, T soudanense, Trichophyton rubrum, and T violaceum are common causes.

• Favus: In this pattern, T schoenleinii is a common cause, and hairs grow to considerable lengths above the scalp with less damage than the other patterns. The hair shafts present with characteristic air spaces, and hyphae form clusters at the level of the epidermis.

Diagnosis

Optimal treatment of TC relies on proper identification of the causative agent. Fungal culture remains the gold standard of mycologic diagnosis regardless of its delayed results, which may take up to 4 weeks for proper identification of the fungal colonies and require ample expertise to interpret the morphologic features of the grown colonies.⁴

Other tests such as the potassium hydroxide preparation are nonspecific and do not identify the dermatophyte species. Although this method has been reported to have 5% to 15% false-negative results in routine practice depending on the skill of the observer and the quality of sampling, microscopic examination is essential, as it may allow the clinician to start treatment sooner pending culture results. The use of a Wood lamp is not suitable for definitive species identification, as this technique primarily is useful for observing fluorescence in ectothrix infection caused by Microsporum species, with the exception of T schoenleinii; otherwise, Trichophyton species, which cause endothrix infections, do not fluoresce.⁵Polymerase chain reaction is a sensitive technique that can help identify both the genus and species of common dermatophytes. Common target sequences include the ribosomal internal transcribed spacer and translation elongation factor 1α. The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also has become popular for dermatophyte identification.⁶Trichoscopic diagnosis of TC, which is simple and noninvasive, is becoming increasingly popular. Features such as short, broken, black dot, comma, corkscrew, and/or zigzag hairs, as well as perifollicular scaling, are helpful for diagnosing TC (Figure). Moreover, trichoscopy can be useful for differentiating other common causes of hair loss, such as trichotillomania and alopecia areata. It had been reported that the trichoscopic features of TC can be seen as early as 2 weeks after starting treatment and therefore this can be a reliable period in which to follow-up with the patient to evaluate progress. The disappearance of black dots and comma hairs can be appreciated from 2 weeks onwards by trichoscopic evaluation.⁴

Treatment

The common recommendation for first-line treatment of TC is the use of systemic antifungals with the use of a topical agent as an adjuvant to prevent the spread of fungal spores. For almost 6 decades, griseofulvin had been the gold-standard fungistatic used for treating TC in patients older than 2 years until the 2007 US Food and Drug Administration (FDA) approval of terbinafine fungicidal oral granules for treatment of TC in patients older than 4 years.⁷

Meta-analyses have demonstrated comparable efficacy for a 4-week course of terbinafine compared to 6 weeks of griseofulvin for TC based on the infectious organism. Terbinafine demonstrated superiority in treating T tonsurans and a similar efficacy in treating T violaceum, while griseofulvin was superior in treating M canis and other Microsporum species.^8,9

The off-label use of fluconazole and itraconazole to treat TC is gaining popularity, with limited trials showing increased evidence of their effectiveness. There is not much clinical evidence to support the use of other oral antifungals, including the newer azoles such as voriconazole or posaconazole.⁹

Newer limited evidence has shown the off-label use of photodynamic therapy to be a promising alternative to systemic antifungal therapy in treating TC, pending validation by larger sample trials.¹⁰In my practice, I have found that severe cases of TC demonstrating inflammation or possible widespread id reactions are better treated with oral steroids. Ketoconazole shampoo or selenium sulfide used 2 to 3 times weekly to prevent spread in the early phases of therapy is a good adjunct to systemic treatment. Cases with kerions should be assessed for the possibility of a coexisting bacterial infection under the crusts, and if confirmed, antibiotics should be started.⁹The commonly used systemic antifungals generally are safe with a low side-effect profile, but there is a risk for hepatotoxicity. The FDA recommends that baseline alanine transaminase and aspartate transaminase levels should be obtained prior to beginning a terbinafine-based treatment regimen.¹¹ The American Academy of Pediatrics has specifically stated that laboratory testing of serum hepatic enzymes is not a requirement if a griseofulvin-based regimen does not exceed 8 weeks; however, transaminase levels (alanine transaminase and aspartate transaminase) should be considered in patients using terbinafine at baseline or if treatment is prolonged beyond 4 to 6 weeks.¹² In agreement with the FDA guidelines, the Canadian Pediatric Society has suggested that liver enzymes should be periodically monitored in patients being treated with terbinafine beyond 4 to 6 weeks.¹³

Changes in the Fungal Microbiome

Research has shown that changes in the fungal microbiome were associated with an altered bacterial community in patients with TC. During fungal infection, the relative abundances of Cutibacterium and Corynebacterium increased, and the relative abundance of Streptococcus decreased. In addition, some uncommon bacterial genera such as Herbaspirillum and Methylorubrum were detected on the scalp in TC.¹⁴

Carrier State

Carrier state is determined for those siblings and contacts of cases with a clinically normal scalp that are positive on culture. Those individuals could represent a potential reservoir responsible for contamination (or recontamination) of the patient as well as treatment failure. Opinions remain divided as to whether to use oral antifungal therapy in these carriers or maintain therapy on antifungal shampoos containing ketoconazole or povidone-iodine. Due to the paucity of available data, my experience has shown that it is sufficient to use antifungal shampoos for such carriers. In zoophilic infections, it is important to identify and treat the animal source.^6-9

Final Thoughts

Successful treatment of TC requires accurate identification of the pathogen, which commonly is achieved via fungal culture. Despite its practical value, the conventional identification of dermatophytes based on morphologic features can be highly challenging due to the low positive rate and delayed results. Trichoscopy is a quick, handy, and noninvasive tool that can better indicate the diagnosis and also is helpful for follow-up on treatment progress. Due to better understanding of the immunology and genetic susceptibility associated with TC spread, the current treatment pipeline holds more insight into better control of this condition. Increased surveillance, prompt diagnosis, and early onset of systemic treatment are the key to proper prevention of spread of TC.

The American College of Cardiology and the American Heart Association have published an updated guideline on the diagnosis and management of aortic disease, focusing on surgical intervention considerations, consistent imaging practices, genetic and familial screenings, and the importance of multidisciplinary care.

“There has been a host of new evidence-based research available for clinicians in the past decade when it comes to aortic disease. It was time to reevaluate and update the previous, existing guidelines,” Eric M. Isselbacher, MD, MSc, chair of the writing committee, said in a statement.

“We hope this new guideline can inform clinical practices with up-to-date and synthesized recommendations, targeted toward a full multidisciplinary aortic team working to provide the best possible care for this vulnerable patient population,” added Dr. Isselbacher, codirector of the Thoracic Aortic Center at Massachusetts General Hospital, Boston.

The 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease was simultaneously published online in the Journal of the American College of Cardiology and Circulation.

The new guideline replaces the 2010 ACCF/AHA Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease and the 2015 Surgery for Aortic Dilation in Patients With Bicuspid Aortic Valves: A Statement of Clarification From the ACC/AHA Task Force on Clinical Practice Guidelines.

The new guideline is intended to be used with the 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease.

It brings together guidelines for both the thoracic and abdominal aorta and is targeted to cardiovascular clinicians involved in the care of people with aortic disease, including general cardiovascular care clinicians and emergency medicine clinicians, the writing group says.

Among the key recommendations in the new guideline are the following:

• Screen first-degree relatives of individuals diagnosed with aneurysms of the aortic root or ascending thoracic aorta, or those with aortic dissection to identify individuals most at risk for aortic disease. Screening would include genetic testing and imaging.
• Be consistent in the way CT or MRI are obtained and reported; in the measurement of aortic size and features; and in how often images are used for monitoring before and after repair surgery or other intervention. Ideally, all surveillance imaging for an individual should be done using the same modality and in the same lab, the guideline notes.
• For individuals who require aortic intervention, know that outcomes are optimized when surgery is performed by an experienced surgeon working in a multidisciplinary aortic team. The new guideline recommends “a specialized hospital team with expertise in the evaluation and management of aortic disease, in which care is delivered in a comprehensive, multidisciplinary manner.”
• At centers with multidisciplinary aortic teams and experienced surgeons, the threshold for surgical intervention for sporadic aortic root and ascending aortic aneurysms has been lowered from 5.5 cm to 5.0 cm in select individuals, and even lower in specific scenarios among patients with heritable thoracic aortic aneurysms.
• In patients who are significantly smaller or taller than average, surgical thresholds may incorporate indexing of the aortic root or ascending aortic diameter to either patient body surface area or height, or aortic cross-sectional area to patient height.
• Rapid aortic growth is a risk factor for rupture and the definition for rapid aneurysm growth rate has been updated. Surgery is now recommended for patients with aneurysms of aortic root and ascending thoracic aorta with a confirmed growth rate of ≥ 0.3 cm per year across 2 consecutive years or ≥ 0.5 cm in 1 year.
• In patients undergoing aortic root replacement surgery, valve-sparing aortic root replacement is reasonable if the valve is suitable for repair and when performed by experienced surgeons in a multidisciplinary aortic team.
• Patients with acute type A aortic dissection, if clinically stable, should be considered for transfer to a high-volume aortic center to improve survival. The operative repair of type A aortic dissection should entail at least an open distal anastomosis rather than just a simple supracoronary interposition graft.
• For management of uncomplicated type B aortic dissection, there is an increasing role for . Clinical trials of repair of thoracoabdominal aortic aneurysms with endografts are reporting results that suggest endovascular repair is an option for patients with suitable anatomy.
• Shared decision-making between the patient and multidisciplinary aortic team is highly encouraged, especially when the patient is on the borderline of thresholds for repair or eligible for different types of surgical repair.
• Shared decision-making should also be used with individuals who are pregnant or may become pregnant to consider the risks of pregnancy in individuals with aortic disease.

The guideline was developed in collaboration with and endorsed by the American Association for Thoracic Surgery, the American College of Radiology, the Society of Cardiovascular Anesthesiologists, the Society for Cardiovascular Angiography and Interventions, the Society of Thoracic Surgeons, and the Society for Vascular Medicine.

It has been endorsed by the Society of Interventional Radiology and the Society for Vascular Surgery.

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

The American College of Cardiology and the American Heart Association have published an updated guideline on the diagnosis and management of aortic disease, focusing on surgical intervention considerations, consistent imaging practices, genetic and familial screenings, and the importance of multidisciplinary care.

“There has been a host of new evidence-based research available for clinicians in the past decade when it comes to aortic disease. It was time to reevaluate and update the previous, existing guidelines,” Eric M. Isselbacher, MD, MSc, chair of the writing committee, said in a statement.

“We hope this new guideline can inform clinical practices with up-to-date and synthesized recommendations, targeted toward a full multidisciplinary aortic team working to provide the best possible care for this vulnerable patient population,” added Dr. Isselbacher, codirector of the Thoracic Aortic Center at Massachusetts General Hospital, Boston.

The 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease was simultaneously published online in the Journal of the American College of Cardiology and Circulation.

The new guideline replaces the 2010 ACCF/AHA Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease and the 2015 Surgery for Aortic Dilation in Patients With Bicuspid Aortic Valves: A Statement of Clarification From the ACC/AHA Task Force on Clinical Practice Guidelines.

The new guideline is intended to be used with the 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease.

It brings together guidelines for both the thoracic and abdominal aorta and is targeted to cardiovascular clinicians involved in the care of people with aortic disease, including general cardiovascular care clinicians and emergency medicine clinicians, the writing group says.

Among the key recommendations in the new guideline are the following:

• Screen first-degree relatives of individuals diagnosed with aneurysms of the aortic root or ascending thoracic aorta, or those with aortic dissection to identify individuals most at risk for aortic disease. Screening would include genetic testing and imaging.
• Be consistent in the way CT or MRI are obtained and reported; in the measurement of aortic size and features; and in how often images are used for monitoring before and after repair surgery or other intervention. Ideally, all surveillance imaging for an individual should be done using the same modality and in the same lab, the guideline notes.
• For individuals who require aortic intervention, know that outcomes are optimized when surgery is performed by an experienced surgeon working in a multidisciplinary aortic team. The new guideline recommends “a specialized hospital team with expertise in the evaluation and management of aortic disease, in which care is delivered in a comprehensive, multidisciplinary manner.”
• At centers with multidisciplinary aortic teams and experienced surgeons, the threshold for surgical intervention for sporadic aortic root and ascending aortic aneurysms has been lowered from 5.5 cm to 5.0 cm in select individuals, and even lower in specific scenarios among patients with heritable thoracic aortic aneurysms.
• In patients who are significantly smaller or taller than average, surgical thresholds may incorporate indexing of the aortic root or ascending aortic diameter to either patient body surface area or height, or aortic cross-sectional area to patient height.
• Rapid aortic growth is a risk factor for rupture and the definition for rapid aneurysm growth rate has been updated. Surgery is now recommended for patients with aneurysms of aortic root and ascending thoracic aorta with a confirmed growth rate of ≥ 0.3 cm per year across 2 consecutive years or ≥ 0.5 cm in 1 year.
• In patients undergoing aortic root replacement surgery, valve-sparing aortic root replacement is reasonable if the valve is suitable for repair and when performed by experienced surgeons in a multidisciplinary aortic team.
• Patients with acute type A aortic dissection, if clinically stable, should be considered for transfer to a high-volume aortic center to improve survival. The operative repair of type A aortic dissection should entail at least an open distal anastomosis rather than just a simple supracoronary interposition graft.
• For management of uncomplicated type B aortic dissection, there is an increasing role for . Clinical trials of repair of thoracoabdominal aortic aneurysms with endografts are reporting results that suggest endovascular repair is an option for patients with suitable anatomy.
• Shared decision-making between the patient and multidisciplinary aortic team is highly encouraged, especially when the patient is on the borderline of thresholds for repair or eligible for different types of surgical repair.
• Shared decision-making should also be used with individuals who are pregnant or may become pregnant to consider the risks of pregnancy in individuals with aortic disease.

The guideline was developed in collaboration with and endorsed by the American Association for Thoracic Surgery, the American College of Radiology, the Society of Cardiovascular Anesthesiologists, the Society for Cardiovascular Angiography and Interventions, the Society of Thoracic Surgeons, and the Society for Vascular Medicine.

It has been endorsed by the Society of Interventional Radiology and the Society for Vascular Surgery.

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

The American College of Cardiology and the American Heart Association have published an updated guideline on the diagnosis and management of aortic disease, focusing on surgical intervention considerations, consistent imaging practices, genetic and familial screenings, and the importance of multidisciplinary care.

“There has been a host of new evidence-based research available for clinicians in the past decade when it comes to aortic disease. It was time to reevaluate and update the previous, existing guidelines,” Eric M. Isselbacher, MD, MSc, chair of the writing committee, said in a statement.

“We hope this new guideline can inform clinical practices with up-to-date and synthesized recommendations, targeted toward a full multidisciplinary aortic team working to provide the best possible care for this vulnerable patient population,” added Dr. Isselbacher, codirector of the Thoracic Aortic Center at Massachusetts General Hospital, Boston.

The 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease was simultaneously published online in the Journal of the American College of Cardiology and Circulation.

The new guideline replaces the 2010 ACCF/AHA Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease and the 2015 Surgery for Aortic Dilation in Patients With Bicuspid Aortic Valves: A Statement of Clarification From the ACC/AHA Task Force on Clinical Practice Guidelines.

The new guideline is intended to be used with the 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease.

It brings together guidelines for both the thoracic and abdominal aorta and is targeted to cardiovascular clinicians involved in the care of people with aortic disease, including general cardiovascular care clinicians and emergency medicine clinicians, the writing group says.

Among the key recommendations in the new guideline are the following:

• Screen first-degree relatives of individuals diagnosed with aneurysms of the aortic root or ascending thoracic aorta, or those with aortic dissection to identify individuals most at risk for aortic disease. Screening would include genetic testing and imaging.
• Be consistent in the way CT or MRI are obtained and reported; in the measurement of aortic size and features; and in how often images are used for monitoring before and after repair surgery or other intervention. Ideally, all surveillance imaging for an individual should be done using the same modality and in the same lab, the guideline notes.
• For individuals who require aortic intervention, know that outcomes are optimized when surgery is performed by an experienced surgeon working in a multidisciplinary aortic team. The new guideline recommends “a specialized hospital team with expertise in the evaluation and management of aortic disease, in which care is delivered in a comprehensive, multidisciplinary manner.”
• At centers with multidisciplinary aortic teams and experienced surgeons, the threshold for surgical intervention for sporadic aortic root and ascending aortic aneurysms has been lowered from 5.5 cm to 5.0 cm in select individuals, and even lower in specific scenarios among patients with heritable thoracic aortic aneurysms.
• In patients who are significantly smaller or taller than average, surgical thresholds may incorporate indexing of the aortic root or ascending aortic diameter to either patient body surface area or height, or aortic cross-sectional area to patient height.
• Rapid aortic growth is a risk factor for rupture and the definition for rapid aneurysm growth rate has been updated. Surgery is now recommended for patients with aneurysms of aortic root and ascending thoracic aorta with a confirmed growth rate of ≥ 0.3 cm per year across 2 consecutive years or ≥ 0.5 cm in 1 year.
• In patients undergoing aortic root replacement surgery, valve-sparing aortic root replacement is reasonable if the valve is suitable for repair and when performed by experienced surgeons in a multidisciplinary aortic team.
• Patients with acute type A aortic dissection, if clinically stable, should be considered for transfer to a high-volume aortic center to improve survival. The operative repair of type A aortic dissection should entail at least an open distal anastomosis rather than just a simple supracoronary interposition graft.
• For management of uncomplicated type B aortic dissection, there is an increasing role for . Clinical trials of repair of thoracoabdominal aortic aneurysms with endografts are reporting results that suggest endovascular repair is an option for patients with suitable anatomy.
• Shared decision-making between the patient and multidisciplinary aortic team is highly encouraged, especially when the patient is on the borderline of thresholds for repair or eligible for different types of surgical repair.
• Shared decision-making should also be used with individuals who are pregnant or may become pregnant to consider the risks of pregnancy in individuals with aortic disease.

The guideline was developed in collaboration with and endorsed by the American Association for Thoracic Surgery, the American College of Radiology, the Society of Cardiovascular Anesthesiologists, the Society for Cardiovascular Angiography and Interventions, the Society of Thoracic Surgeons, and the Society for Vascular Medicine.

It has been endorsed by the Society of Interventional Radiology and the Society for Vascular Surgery.

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