MDedge Dermatology

Practice Gap

Onychocryptosis, colloquially known as an ingrown nail, most commonly affects the lateral folds of the toenails. It also can affect the fingernails and the distal aspect of the nail unit, though these presentations are not as well described in the literature. In onychocryptosis, the nail plate grows downward into the periungual skin, resulting in chronic pain and inflammation. Risk factors include overtrimming the nails with rounded edges, local trauma, nail surgery, wearing tight footwear, obesity, and onychomycosis.¹

Although surgical intervention might be required for severe or refractory disease, conservative treatment options are first line and often curative. A variety of techniques have been designed to separate the ingrown portion of the nail plate from underlying skin, including placement of an intervening piece of dental floss, cotton, or plastic tubing.²

Anchor taping is another effective method of treating onychocryptosis; a strip of tape is used to gently pull and secure the affected nail fold away from the overlying nail plate. This technique has been well described for the treatment of onychocryptosis of the lateral toenail.^3-5 In 2017, Arai and Haneke⁵ presented a modified technique for the treatment of distal disease.

We present a simplified method that was used successfully in a case of distal onychocryptosis of the thumbnail that occurred approximately 4 months after complete nail avulsion with a nail matrix biopsy (Figure 1).

The Technique

A strongly adhesive, soft cotton, elastic tape that is 1-inch wide, such as Elastikon Elastic Tape (Johnson & Johnson), is used to pull and secure the hyponychium away from the overlying nail plate. When this technique is used for lateral onychocryptosis, a single strip of tape is secured to the affected lateral nail fold, pulled obliquely and proximally, and secured to the base of the digit.^3-5 In the Arai and Haneke⁵ method for the treatment of distal disease, a piece of tape is first placed at the distal nail fold, pulled proximally, and secured to the ventral aspect of the digit. Then, 1 or 2 additional strips of tape are applied to the lateral nail folds, pulled obliquely, and adhered to the base of the digit, as in the classic technique for lateral onychocryptosis.⁵

In our modification for the treatment of distal disease, only 2 strips of tape are required, each approximately 5-cm long. The first strip of tape is applied to the hyponychium parallel to the long axis of the finger, pulled away from the distal edge of the nail plate, and secured obliquely and proximally to the base of the finger on one side. The second strip of tape is applied to the hyponychium in the same manner, directly overlying the first strip, but is then pulled obliquely in the opposite direction and secured to the other side of the proximal finger (Figure 2). The 2 strips of tape are applied directly overlying each other at the distal nail fold but with opposing tension vectors to optimize pull on the distal nail fold. This modification eliminates the need to apply an initial strip of tape along the long axis of the digit, as described by Arai and Haneke.⁵

Practice Implications

Anchor taping is a common and effective treatment of onychocryptosis. Most techniques described in the literature are for lateral toenail cases, which often are managed by podiatry. A modification for the treatment of distal onychocryptosis has been previously described.⁵ We describe a similar modification using 2 tape strips pulled in opposite directions, which successfully resolved a case of distal onychocryptosis of the fingernail that developed following a nail procedure.

Because nail dystrophy is a relatively common complication of nail surgery, dermatologic surgeons should be aware of this simple, cost-effective, and noninvasive technique for the treatment of distal onychocryptosis.

Practice Gap

Onychocryptosis, colloquially known as an ingrown nail, most commonly affects the lateral folds of the toenails. It also can affect the fingernails and the distal aspect of the nail unit, though these presentations are not as well described in the literature. In onychocryptosis, the nail plate grows downward into the periungual skin, resulting in chronic pain and inflammation. Risk factors include overtrimming the nails with rounded edges, local trauma, nail surgery, wearing tight footwear, obesity, and onychomycosis.¹

Although surgical intervention might be required for severe or refractory disease, conservative treatment options are first line and often curative. A variety of techniques have been designed to separate the ingrown portion of the nail plate from underlying skin, including placement of an intervening piece of dental floss, cotton, or plastic tubing.²

Anchor taping is another effective method of treating onychocryptosis; a strip of tape is used to gently pull and secure the affected nail fold away from the overlying nail plate. This technique has been well described for the treatment of onychocryptosis of the lateral toenail.^3-5 In 2017, Arai and Haneke⁵ presented a modified technique for the treatment of distal disease.

We present a simplified method that was used successfully in a case of distal onychocryptosis of the thumbnail that occurred approximately 4 months after complete nail avulsion with a nail matrix biopsy (Figure 1).

The Technique

A strongly adhesive, soft cotton, elastic tape that is 1-inch wide, such as Elastikon Elastic Tape (Johnson & Johnson), is used to pull and secure the hyponychium away from the overlying nail plate. When this technique is used for lateral onychocryptosis, a single strip of tape is secured to the affected lateral nail fold, pulled obliquely and proximally, and secured to the base of the digit.^3-5 In the Arai and Haneke⁵ method for the treatment of distal disease, a piece of tape is first placed at the distal nail fold, pulled proximally, and secured to the ventral aspect of the digit. Then, 1 or 2 additional strips of tape are applied to the lateral nail folds, pulled obliquely, and adhered to the base of the digit, as in the classic technique for lateral onychocryptosis.⁵

In our modification for the treatment of distal disease, only 2 strips of tape are required, each approximately 5-cm long. The first strip of tape is applied to the hyponychium parallel to the long axis of the finger, pulled away from the distal edge of the nail plate, and secured obliquely and proximally to the base of the finger on one side. The second strip of tape is applied to the hyponychium in the same manner, directly overlying the first strip, but is then pulled obliquely in the opposite direction and secured to the other side of the proximal finger (Figure 2). The 2 strips of tape are applied directly overlying each other at the distal nail fold but with opposing tension vectors to optimize pull on the distal nail fold. This modification eliminates the need to apply an initial strip of tape along the long axis of the digit, as described by Arai and Haneke.⁵

Practice Implications

Anchor taping is a common and effective treatment of onychocryptosis. Most techniques described in the literature are for lateral toenail cases, which often are managed by podiatry. A modification for the treatment of distal onychocryptosis has been previously described.⁵ We describe a similar modification using 2 tape strips pulled in opposite directions, which successfully resolved a case of distal onychocryptosis of the fingernail that developed following a nail procedure.

Because nail dystrophy is a relatively common complication of nail surgery, dermatologic surgeons should be aware of this simple, cost-effective, and noninvasive technique for the treatment of distal onychocryptosis.

Practice Gap

Onychocryptosis, colloquially known as an ingrown nail, most commonly affects the lateral folds of the toenails. It also can affect the fingernails and the distal aspect of the nail unit, though these presentations are not as well described in the literature. In onychocryptosis, the nail plate grows downward into the periungual skin, resulting in chronic pain and inflammation. Risk factors include overtrimming the nails with rounded edges, local trauma, nail surgery, wearing tight footwear, obesity, and onychomycosis.¹

Although surgical intervention might be required for severe or refractory disease, conservative treatment options are first line and often curative. A variety of techniques have been designed to separate the ingrown portion of the nail plate from underlying skin, including placement of an intervening piece of dental floss, cotton, or plastic tubing.²

Anchor taping is another effective method of treating onychocryptosis; a strip of tape is used to gently pull and secure the affected nail fold away from the overlying nail plate. This technique has been well described for the treatment of onychocryptosis of the lateral toenail.^3-5 In 2017, Arai and Haneke⁵ presented a modified technique for the treatment of distal disease.

We present a simplified method that was used successfully in a case of distal onychocryptosis of the thumbnail that occurred approximately 4 months after complete nail avulsion with a nail matrix biopsy (Figure 1).

The Technique

A strongly adhesive, soft cotton, elastic tape that is 1-inch wide, such as Elastikon Elastic Tape (Johnson & Johnson), is used to pull and secure the hyponychium away from the overlying nail plate. When this technique is used for lateral onychocryptosis, a single strip of tape is secured to the affected lateral nail fold, pulled obliquely and proximally, and secured to the base of the digit.^3-5 In the Arai and Haneke⁵ method for the treatment of distal disease, a piece of tape is first placed at the distal nail fold, pulled proximally, and secured to the ventral aspect of the digit. Then, 1 or 2 additional strips of tape are applied to the lateral nail folds, pulled obliquely, and adhered to the base of the digit, as in the classic technique for lateral onychocryptosis.⁵

In our modification for the treatment of distal disease, only 2 strips of tape are required, each approximately 5-cm long. The first strip of tape is applied to the hyponychium parallel to the long axis of the finger, pulled away from the distal edge of the nail plate, and secured obliquely and proximally to the base of the finger on one side. The second strip of tape is applied to the hyponychium in the same manner, directly overlying the first strip, but is then pulled obliquely in the opposite direction and secured to the other side of the proximal finger (Figure 2). The 2 strips of tape are applied directly overlying each other at the distal nail fold but with opposing tension vectors to optimize pull on the distal nail fold. This modification eliminates the need to apply an initial strip of tape along the long axis of the digit, as described by Arai and Haneke.⁵

Practice Implications

Anchor taping is a common and effective treatment of onychocryptosis. Most techniques described in the literature are for lateral toenail cases, which often are managed by podiatry. A modification for the treatment of distal onychocryptosis has been previously described.⁵ We describe a similar modification using 2 tape strips pulled in opposite directions, which successfully resolved a case of distal onychocryptosis of the fingernail that developed following a nail procedure.

Because nail dystrophy is a relatively common complication of nail surgery, dermatologic surgeons should be aware of this simple, cost-effective, and noninvasive technique for the treatment of distal onychocryptosis.

Most adverse events associated with the practice of microneedling are transient, and most adverse effects and allergic reactions occur in conjunction with combination therapies, according to the results of a systematic review of nearly 3,000 patients.

marcinm111/iStock/Getty Images

Microneedling involves the use of instruments including dermarollers and microneedling pens to cause controlled microtraumas at various skin depths and induce a wounding cascade that ultimately improves the visual appearance of the skin, Sherman Chu, DO, of the department of dermatology at the University of California, Irvine, and colleagues wrote.

Microneedling has increased in popularity because of its relatively low cost, effectiveness, and ease of use, and is often promoted as “a safe alternative treatment, particularly in skin of color, but the safety of microneedling and its complications are not often discussed,” the researchers noted.

In the study, published in Dermatologic Surgery, Dr. Chu and coauthors identified 85 articles for the systematic review of safety data on microneedling. The studies included 30 randomized, controlled trials; 24 prospective studies; 16 case series; 12 case reports; and 3 retrospective cohort studies, with a total of 2,805 patients treated with microneedling.

The devices used in the studies were primarily dermarollers (1,758 procedures), but 425 procedures involved dermapens, and 176 involved unidentified microneedling devices.

The most common adverse effect after microneedling with any device was any of anticipated transient procedural side effects including transient erythema or edema, pain, burning, bruising, pruritus, stinging, bleeding, crusting, and desquamation. Overall, these effects resolved within a week with little or no treatment, the researchers said.

The most commonly reported postprocedure side effects of microneedling were postinflammatory hyperpigmentation (46 incidents), followed by dry skin and exfoliation (41 incidents). Fewer than 15 incidents were reported of each the following: acne flare, pruritus, persistent erythema, herpetic infection, flushing, seborrheic dermatitis, burning, headache, stinging, milia, tram-track scarring, facial allergic granulomatous reaction and systematic hypersensitivity, and tender cervical lymphadenopathy. In addition, one incident each was reported of periorbital dermatitis, phototoxic reaction, pressure urticaria, irritant contact dermatitis, widespread facial inoculation of varicella, pustular folliculitis, and tinea corporis.

The studies suggest that microneedling is generally well tolerated, the researchers wrote. Factors that increased the risk of adverse events included the presence of active infections, darker skin types, metal allergies, and the use of combination therapies. For example, they noted, one randomized, controlled trial showed greater skin irritation in patients treated with both microneedling and tranexamic acid compared with those treated with tranexamic acid alone.

Other studies described increased risk of postinflammatory hyperpigmentation in patients treated with both microneedling and platelet-rich plasma, and with microneedling and topical 5-FU or tacrolimus. Also, in one of the studies in the review, “the development of a delayed granulomatous hypersensitivity reaction in 2 patients was attributed to a reaction to vitamin C serum, whereas another study attributes vitamin A and vitamin C oil to be the cause of a patient’s prolonged erythema and pruritus,” the researchers said.

The study findings were limited to adverse events reported by clinicians in published literature, and did not account for adverse events that occur when microneedling is performed at home or in medical spas. Although the results suggest that microneedling is relatively safe for patients of most skin types, “great caution should be taken when performing microneedling with products not approved to be used intradermally,” they emphasized.

“Further studies are needed to determine which patients are at a higher chance of developing scarring because depth of the needle and skin type do not directly correlate as initially believed,” they concluded.

Microneedling offers safe alternative to lasers

“Microneedling is a popular procedure that can be used as an alternative to laser treatments to provide low down time, and lower-cost treatments for similar indications in which lasers are used, such as rhytides and scars,” Catherine M. DiGiorgio, MD, a laser and cosmetic dermatologist at the Boston Center for Facial Rejuvenation, said in an interview.

“Many clinicians and/or providers utilize microneedling in their practice also because they may not have the ability to perform laser and energy-based device treatments,” noted Dr. DiGiorgio, who was asked to comment on the study findings. “Microneedling is safer than energy-based devices in darker skin types due to the lack of energy or heat being delivered to the epidermis. However, as shown in this study, darker skin types remain at risk for [postinflammatory hyperpigmentation], particularly in the hands of an unskilled, inexperienced operator.”

Dr. DiGiorgio said she was not surprised by the study findings. “Microneedling creates microwounds in the skin, which contributes to the risk of all of the side effects listed in the study. Further, the proper use of microneedling devices by the providers performing the procedure is variable and depths of penetration can vary based on which device or roller pen is used and the experience of the person performing the procedures. Depth, after a certain point, can be inaccurate and can superficially abrade the epidermis rather than the intended individual microneedle punctures.”

Laser and energy-based device treatments can be performed safely in patients with darker skin types in the hands of skilled and experienced laser surgeons, said Dr. DiGiorgio. However, “more studies are needed to determine the effectiveness of microneedling alone compared to other treatment modalities. Patients tend to select microneedling due to affordability and less down time; however, sometimes it may not be the best treatment option for their skin condition.

“Patient education is an important factor because one treatment that worked for one of their friends, for example, may not be the best treatment option for their skin complaints.”

Dr. DiGiorgio added that there are few randomized, controlled trials comparing microneedling to laser treatment. “More studies of this nature would benefit the scientific literature and the addition of histological analysis would help us better understand how these treatments compare on a microscopic level.”

The study received no outside funding and the author has no disclosures. Dr. DiGiorgio has served as a consultant for Allergan Aesthetics.

Most adverse events associated with the practice of microneedling are transient, and most adverse effects and allergic reactions occur in conjunction with combination therapies, according to the results of a systematic review of nearly 3,000 patients.

marcinm111/iStock/Getty Images

Microneedling involves the use of instruments including dermarollers and microneedling pens to cause controlled microtraumas at various skin depths and induce a wounding cascade that ultimately improves the visual appearance of the skin, Sherman Chu, DO, of the department of dermatology at the University of California, Irvine, and colleagues wrote.

Microneedling has increased in popularity because of its relatively low cost, effectiveness, and ease of use, and is often promoted as “a safe alternative treatment, particularly in skin of color, but the safety of microneedling and its complications are not often discussed,” the researchers noted.

In the study, published in Dermatologic Surgery, Dr. Chu and coauthors identified 85 articles for the systematic review of safety data on microneedling. The studies included 30 randomized, controlled trials; 24 prospective studies; 16 case series; 12 case reports; and 3 retrospective cohort studies, with a total of 2,805 patients treated with microneedling.

The devices used in the studies were primarily dermarollers (1,758 procedures), but 425 procedures involved dermapens, and 176 involved unidentified microneedling devices.

The most common adverse effect after microneedling with any device was any of anticipated transient procedural side effects including transient erythema or edema, pain, burning, bruising, pruritus, stinging, bleeding, crusting, and desquamation. Overall, these effects resolved within a week with little or no treatment, the researchers said.

The most commonly reported postprocedure side effects of microneedling were postinflammatory hyperpigmentation (46 incidents), followed by dry skin and exfoliation (41 incidents). Fewer than 15 incidents were reported of each the following: acne flare, pruritus, persistent erythema, herpetic infection, flushing, seborrheic dermatitis, burning, headache, stinging, milia, tram-track scarring, facial allergic granulomatous reaction and systematic hypersensitivity, and tender cervical lymphadenopathy. In addition, one incident each was reported of periorbital dermatitis, phototoxic reaction, pressure urticaria, irritant contact dermatitis, widespread facial inoculation of varicella, pustular folliculitis, and tinea corporis.

The studies suggest that microneedling is generally well tolerated, the researchers wrote. Factors that increased the risk of adverse events included the presence of active infections, darker skin types, metal allergies, and the use of combination therapies. For example, they noted, one randomized, controlled trial showed greater skin irritation in patients treated with both microneedling and tranexamic acid compared with those treated with tranexamic acid alone.

Other studies described increased risk of postinflammatory hyperpigmentation in patients treated with both microneedling and platelet-rich plasma, and with microneedling and topical 5-FU or tacrolimus. Also, in one of the studies in the review, “the development of a delayed granulomatous hypersensitivity reaction in 2 patients was attributed to a reaction to vitamin C serum, whereas another study attributes vitamin A and vitamin C oil to be the cause of a patient’s prolonged erythema and pruritus,” the researchers said.

The study findings were limited to adverse events reported by clinicians in published literature, and did not account for adverse events that occur when microneedling is performed at home or in medical spas. Although the results suggest that microneedling is relatively safe for patients of most skin types, “great caution should be taken when performing microneedling with products not approved to be used intradermally,” they emphasized.

“Further studies are needed to determine which patients are at a higher chance of developing scarring because depth of the needle and skin type do not directly correlate as initially believed,” they concluded.

Microneedling offers safe alternative to lasers

“Microneedling is a popular procedure that can be used as an alternative to laser treatments to provide low down time, and lower-cost treatments for similar indications in which lasers are used, such as rhytides and scars,” Catherine M. DiGiorgio, MD, a laser and cosmetic dermatologist at the Boston Center for Facial Rejuvenation, said in an interview.

“Many clinicians and/or providers utilize microneedling in their practice also because they may not have the ability to perform laser and energy-based device treatments,” noted Dr. DiGiorgio, who was asked to comment on the study findings. “Microneedling is safer than energy-based devices in darker skin types due to the lack of energy or heat being delivered to the epidermis. However, as shown in this study, darker skin types remain at risk for [postinflammatory hyperpigmentation], particularly in the hands of an unskilled, inexperienced operator.”

Dr. DiGiorgio said she was not surprised by the study findings. “Microneedling creates microwounds in the skin, which contributes to the risk of all of the side effects listed in the study. Further, the proper use of microneedling devices by the providers performing the procedure is variable and depths of penetration can vary based on which device or roller pen is used and the experience of the person performing the procedures. Depth, after a certain point, can be inaccurate and can superficially abrade the epidermis rather than the intended individual microneedle punctures.”

Laser and energy-based device treatments can be performed safely in patients with darker skin types in the hands of skilled and experienced laser surgeons, said Dr. DiGiorgio. However, “more studies are needed to determine the effectiveness of microneedling alone compared to other treatment modalities. Patients tend to select microneedling due to affordability and less down time; however, sometimes it may not be the best treatment option for their skin condition.

“Patient education is an important factor because one treatment that worked for one of their friends, for example, may not be the best treatment option for their skin complaints.”

Dr. DiGiorgio added that there are few randomized, controlled trials comparing microneedling to laser treatment. “More studies of this nature would benefit the scientific literature and the addition of histological analysis would help us better understand how these treatments compare on a microscopic level.”

The study received no outside funding and the author has no disclosures. Dr. DiGiorgio has served as a consultant for Allergan Aesthetics.

Most adverse events associated with the practice of microneedling are transient, and most adverse effects and allergic reactions occur in conjunction with combination therapies, according to the results of a systematic review of nearly 3,000 patients.

marcinm111/iStock/Getty Images

Microneedling involves the use of instruments including dermarollers and microneedling pens to cause controlled microtraumas at various skin depths and induce a wounding cascade that ultimately improves the visual appearance of the skin, Sherman Chu, DO, of the department of dermatology at the University of California, Irvine, and colleagues wrote.

Microneedling has increased in popularity because of its relatively low cost, effectiveness, and ease of use, and is often promoted as “a safe alternative treatment, particularly in skin of color, but the safety of microneedling and its complications are not often discussed,” the researchers noted.

In the study, published in Dermatologic Surgery, Dr. Chu and coauthors identified 85 articles for the systematic review of safety data on microneedling. The studies included 30 randomized, controlled trials; 24 prospective studies; 16 case series; 12 case reports; and 3 retrospective cohort studies, with a total of 2,805 patients treated with microneedling.

The devices used in the studies were primarily dermarollers (1,758 procedures), but 425 procedures involved dermapens, and 176 involved unidentified microneedling devices.

The most common adverse effect after microneedling with any device was any of anticipated transient procedural side effects including transient erythema or edema, pain, burning, bruising, pruritus, stinging, bleeding, crusting, and desquamation. Overall, these effects resolved within a week with little or no treatment, the researchers said.

The most commonly reported postprocedure side effects of microneedling were postinflammatory hyperpigmentation (46 incidents), followed by dry skin and exfoliation (41 incidents). Fewer than 15 incidents were reported of each the following: acne flare, pruritus, persistent erythema, herpetic infection, flushing, seborrheic dermatitis, burning, headache, stinging, milia, tram-track scarring, facial allergic granulomatous reaction and systematic hypersensitivity, and tender cervical lymphadenopathy. In addition, one incident each was reported of periorbital dermatitis, phototoxic reaction, pressure urticaria, irritant contact dermatitis, widespread facial inoculation of varicella, pustular folliculitis, and tinea corporis.

The studies suggest that microneedling is generally well tolerated, the researchers wrote. Factors that increased the risk of adverse events included the presence of active infections, darker skin types, metal allergies, and the use of combination therapies. For example, they noted, one randomized, controlled trial showed greater skin irritation in patients treated with both microneedling and tranexamic acid compared with those treated with tranexamic acid alone.

Other studies described increased risk of postinflammatory hyperpigmentation in patients treated with both microneedling and platelet-rich plasma, and with microneedling and topical 5-FU or tacrolimus. Also, in one of the studies in the review, “the development of a delayed granulomatous hypersensitivity reaction in 2 patients was attributed to a reaction to vitamin C serum, whereas another study attributes vitamin A and vitamin C oil to be the cause of a patient’s prolonged erythema and pruritus,” the researchers said.

The study findings were limited to adverse events reported by clinicians in published literature, and did not account for adverse events that occur when microneedling is performed at home or in medical spas. Although the results suggest that microneedling is relatively safe for patients of most skin types, “great caution should be taken when performing microneedling with products not approved to be used intradermally,” they emphasized.

“Further studies are needed to determine which patients are at a higher chance of developing scarring because depth of the needle and skin type do not directly correlate as initially believed,” they concluded.

Microneedling offers safe alternative to lasers

“Microneedling is a popular procedure that can be used as an alternative to laser treatments to provide low down time, and lower-cost treatments for similar indications in which lasers are used, such as rhytides and scars,” Catherine M. DiGiorgio, MD, a laser and cosmetic dermatologist at the Boston Center for Facial Rejuvenation, said in an interview.

“Many clinicians and/or providers utilize microneedling in their practice also because they may not have the ability to perform laser and energy-based device treatments,” noted Dr. DiGiorgio, who was asked to comment on the study findings. “Microneedling is safer than energy-based devices in darker skin types due to the lack of energy or heat being delivered to the epidermis. However, as shown in this study, darker skin types remain at risk for [postinflammatory hyperpigmentation], particularly in the hands of an unskilled, inexperienced operator.”

Dr. DiGiorgio said she was not surprised by the study findings. “Microneedling creates microwounds in the skin, which contributes to the risk of all of the side effects listed in the study. Further, the proper use of microneedling devices by the providers performing the procedure is variable and depths of penetration can vary based on which device or roller pen is used and the experience of the person performing the procedures. Depth, after a certain point, can be inaccurate and can superficially abrade the epidermis rather than the intended individual microneedle punctures.”

Laser and energy-based device treatments can be performed safely in patients with darker skin types in the hands of skilled and experienced laser surgeons, said Dr. DiGiorgio. However, “more studies are needed to determine the effectiveness of microneedling alone compared to other treatment modalities. Patients tend to select microneedling due to affordability and less down time; however, sometimes it may not be the best treatment option for their skin condition.

“Patient education is an important factor because one treatment that worked for one of their friends, for example, may not be the best treatment option for their skin complaints.”

Dr. DiGiorgio added that there are few randomized, controlled trials comparing microneedling to laser treatment. “More studies of this nature would benefit the scientific literature and the addition of histological analysis would help us better understand how these treatments compare on a microscopic level.”

The study received no outside funding and the author has no disclosures. Dr. DiGiorgio has served as a consultant for Allergan Aesthetics.

Children with severe atopic dermatitis (AD) are about twice as likely to develop depression and internalizing behavior as those without this condition, according to a newly published cohort study of more than 11,000 children between the ages of 3 and 18 years.

Along with previous studies that have also linked AD to depression and other mental health issues in children, these data highlight the need for “clinical awareness of the psychosocial needs of children and adolescents with AD,” reported a multicenter team of investigators from the University of California, San Francisco, the University of Pennsylvania, and the London School of Hygiene and Tropical Medicine.

Unlike some previous studies, in this study, published online in JAMA Dermatology on Sept. 1, children were evaluated longitudinally, rather than at a single point in time, with a mean follow-up of 10 years. For those with active AD, compared with children without AD, the odds ratio for depression overall in any child with AD relative to those without AD was not significant after adjustment for variables such socioeconomic factors.

However, among children with severe AD, the risk was more than twofold greater even after adjustment (adjusted OR, 2.38; 95% confidence interval, 1.21- 4.72), reported the investigators, led by senior author Katrina Abuabara, MD, associate professor of dermatology and epidemiology at UCSF.
 

Internalizing symptoms seen with mild to severe AD

Internalizing behavior, which is closely linked to depression and describes a spectrum of inward-focusing activities, such as social withdrawal, was significantly more common in children with any degree of AD relative to those without AD: After adjustment, the risk climbed from a 29% increased risk in those with mild AD (aOR, 1.29; 95% CI, 1.06-1.57) to a more than 80% increased risk in children with moderate AD (aOR, 1.84; 95% CI, 1.40-2.41) and in children with severe AD (aOR, 1.90; 95% CI, 1.14-3.16).

In the study, depression was measured with the Short Moods and Feelings Questionnaire (SMFQ). Parental response to the Emotional Symptoms subscale of the Strength and Difficulties Questionnaire (SDQ) was used to measure internalizing behaviors.

The data were drawn from the Avon Longitudinal Study for Parents and Children (ALSPAC), a cohort that enrolled pregnant women in a defined area in southwest England and then followed children born from these pregnancies. Of the 14,062 children enrolled in ALSPAC, data from 11,181 children were available for this study.

In a previous meta-analysis of studies that have documented a link between AD and adverse effects on mood and mental health, an impact was identified in both children and adults. In children, AD was associated with a 27% increase in risk of depression (OR, 1.27; 95% CI, 1.12 -1.45). In adults, the risk was more than doubled (OR, 2.19; 95% CI, 1.87-2.57). The same meta-analysis found that the risk of suicidal ideation among adolescents and adults with AD was increased more than fourfold (OR, 4.32; 95% CI, 1.93-9.66).

In the ALSPAC data, the investigators were unable to find compelling evidence that sleep disturbances or concomitant asthma contributed to the increased risk of depression, which is a mechanism proposed by past investigators.

In an interview, Dr. Abuabara said that these and other data provide the basis for encouraging clinical awareness of the psychological needs of children with AD, but she suggested there is a gap in understanding what this means clinically. “We need more data on how dermatologists can effectively screen and manage these patients before we try to set expectations for clinical practice,” she said.

In addition, these data along with previously published studies suggest that change in mental health outcomes should be included in the evaluation of new therapies, according to Dr. Abuabara. She noted that there are several tools for evaluating mental health in children that might be appropriate, each with their own advantages and disadvantages.

“Ideally, recommendations would be issued through a group consensus process with patients, clinicians, researchers, and industry representatives working together as has been done for other outcomes through the Harmonizing Measures for Eczema (HOME) group,” Dr. Abuabara said.

 

Mental health assessments recommended

Others who have looked at the relationship between AD and depression have also recommended adding mental health outcomes to an assessment of efficacy for AD therapies.

Jonathan I. Silverberg, MD, PhD, MPH, associate professor of dermatology, George Washington University, Washington, is one such investigator. He is already monitoring depression systematically with the Hospital Anxiety and Depression Scale (HADS).

“HADS has been validated in AD and provides very important information about the emotional burden of AD,” explained Dr. Silverberg, whose most recent article on this topic appeared earlier this year. In that study, the relationship between AD and depression was found to be more pronounced in White children from families with lower incomes.

“Just a few hours ago, one of my patients thanked me for asking about their mental health and recognizing the holistic effects of AD,” Dr. Silverberg said.

The recent study based on ALSPAC data add to the evidence that AD, particularly severe AD, produces deleterious effects on mental health in children, and Dr. Silverberg believes clinicians should be acting on this evidence.

“I strongly encourage clinicians to routinely assess mental health. It will elevate the quality of care they provide, and their patients will appreciate them more for it,” he said.

Dr. Abuabara and another author report receiving research funding from Pfizer to their universities for unrelated work; there were no other disclosures. Dr. Silverberg reports financial relationships with more than 15 pharmaceutical companies.

Commentary by Lawrence F. Eichenfield, MD

More severe atopic dermatitis (AD) carries with it significant mental health concerns in children, as well as adults. Multiple studies have shown significantly higher rates of depression, anxiety, and “internalizing behaviors” (discussed as social withdrawal and other inward-focused activities) as well as attention-deficit/hyperactivity disorder. The study by Dr. Abuabara and colleagues is important as it followed children over time (an average of 10 years) and adjusted the data for socioeconomic factors, showing a rate of depression in children with severe AD twice that of those without. It appears that we are in the midst of a mental health crisis in children and teens, with markedly higher rates of pediatric and adolescent depression and anxiety, certainly influenced by COVID-19 societal changes. As the literature has developed on depression and AD, we have appreciated the importance of addressing this as part of our assessment of the disease effect on the individual and family, and it is one factor we consider in selections of systemic vs. topical therapies.  

Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children's Hospital-San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. He disclosed that he has served as an investigator and/or consultant to AbbVie, Lilly, Pfizer, Regeneron, Sanofi-Genzyme, and Verrica.

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

This article was updated 6/18/22.

Children with severe atopic dermatitis (AD) are about twice as likely to develop depression and internalizing behavior as those without this condition, according to a newly published cohort study of more than 11,000 children between the ages of 3 and 18 years.

Along with previous studies that have also linked AD to depression and other mental health issues in children, these data highlight the need for “clinical awareness of the psychosocial needs of children and adolescents with AD,” reported a multicenter team of investigators from the University of California, San Francisco, the University of Pennsylvania, and the London School of Hygiene and Tropical Medicine.

Unlike some previous studies, in this study, published online in JAMA Dermatology on Sept. 1, children were evaluated longitudinally, rather than at a single point in time, with a mean follow-up of 10 years. For those with active AD, compared with children without AD, the odds ratio for depression overall in any child with AD relative to those without AD was not significant after adjustment for variables such socioeconomic factors.

However, among children with severe AD, the risk was more than twofold greater even after adjustment (adjusted OR, 2.38; 95% confidence interval, 1.21- 4.72), reported the investigators, led by senior author Katrina Abuabara, MD, associate professor of dermatology and epidemiology at UCSF.
 

Internalizing symptoms seen with mild to severe AD

Internalizing behavior, which is closely linked to depression and describes a spectrum of inward-focusing activities, such as social withdrawal, was significantly more common in children with any degree of AD relative to those without AD: After adjustment, the risk climbed from a 29% increased risk in those with mild AD (aOR, 1.29; 95% CI, 1.06-1.57) to a more than 80% increased risk in children with moderate AD (aOR, 1.84; 95% CI, 1.40-2.41) and in children with severe AD (aOR, 1.90; 95% CI, 1.14-3.16).

In the study, depression was measured with the Short Moods and Feelings Questionnaire (SMFQ). Parental response to the Emotional Symptoms subscale of the Strength and Difficulties Questionnaire (SDQ) was used to measure internalizing behaviors.

The data were drawn from the Avon Longitudinal Study for Parents and Children (ALSPAC), a cohort that enrolled pregnant women in a defined area in southwest England and then followed children born from these pregnancies. Of the 14,062 children enrolled in ALSPAC, data from 11,181 children were available for this study.

In a previous meta-analysis of studies that have documented a link between AD and adverse effects on mood and mental health, an impact was identified in both children and adults. In children, AD was associated with a 27% increase in risk of depression (OR, 1.27; 95% CI, 1.12 -1.45). In adults, the risk was more than doubled (OR, 2.19; 95% CI, 1.87-2.57). The same meta-analysis found that the risk of suicidal ideation among adolescents and adults with AD was increased more than fourfold (OR, 4.32; 95% CI, 1.93-9.66).

In the ALSPAC data, the investigators were unable to find compelling evidence that sleep disturbances or concomitant asthma contributed to the increased risk of depression, which is a mechanism proposed by past investigators.

In an interview, Dr. Abuabara said that these and other data provide the basis for encouraging clinical awareness of the psychological needs of children with AD, but she suggested there is a gap in understanding what this means clinically. “We need more data on how dermatologists can effectively screen and manage these patients before we try to set expectations for clinical practice,” she said.

In addition, these data along with previously published studies suggest that change in mental health outcomes should be included in the evaluation of new therapies, according to Dr. Abuabara. She noted that there are several tools for evaluating mental health in children that might be appropriate, each with their own advantages and disadvantages.

“Ideally, recommendations would be issued through a group consensus process with patients, clinicians, researchers, and industry representatives working together as has been done for other outcomes through the Harmonizing Measures for Eczema (HOME) group,” Dr. Abuabara said.

 

Mental health assessments recommended

Others who have looked at the relationship between AD and depression have also recommended adding mental health outcomes to an assessment of efficacy for AD therapies.

Jonathan I. Silverberg, MD, PhD, MPH, associate professor of dermatology, George Washington University, Washington, is one such investigator. He is already monitoring depression systematically with the Hospital Anxiety and Depression Scale (HADS).

“HADS has been validated in AD and provides very important information about the emotional burden of AD,” explained Dr. Silverberg, whose most recent article on this topic appeared earlier this year. In that study, the relationship between AD and depression was found to be more pronounced in White children from families with lower incomes.

“Just a few hours ago, one of my patients thanked me for asking about their mental health and recognizing the holistic effects of AD,” Dr. Silverberg said.

The recent study based on ALSPAC data add to the evidence that AD, particularly severe AD, produces deleterious effects on mental health in children, and Dr. Silverberg believes clinicians should be acting on this evidence.

“I strongly encourage clinicians to routinely assess mental health. It will elevate the quality of care they provide, and their patients will appreciate them more for it,” he said.

Dr. Abuabara and another author report receiving research funding from Pfizer to their universities for unrelated work; there were no other disclosures. Dr. Silverberg reports financial relationships with more than 15 pharmaceutical companies.

Commentary by Lawrence F. Eichenfield, MD

More severe atopic dermatitis (AD) carries with it significant mental health concerns in children, as well as adults. Multiple studies have shown significantly higher rates of depression, anxiety, and “internalizing behaviors” (discussed as social withdrawal and other inward-focused activities) as well as attention-deficit/hyperactivity disorder. The study by Dr. Abuabara and colleagues is important as it followed children over time (an average of 10 years) and adjusted the data for socioeconomic factors, showing a rate of depression in children with severe AD twice that of those without. It appears that we are in the midst of a mental health crisis in children and teens, with markedly higher rates of pediatric and adolescent depression and anxiety, certainly influenced by COVID-19 societal changes. As the literature has developed on depression and AD, we have appreciated the importance of addressing this as part of our assessment of the disease effect on the individual and family, and it is one factor we consider in selections of systemic vs. topical therapies.  

Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children's Hospital-San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. He disclosed that he has served as an investigator and/or consultant to AbbVie, Lilly, Pfizer, Regeneron, Sanofi-Genzyme, and Verrica.

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

This article was updated 6/18/22.

Children with severe atopic dermatitis (AD) are about twice as likely to develop depression and internalizing behavior as those without this condition, according to a newly published cohort study of more than 11,000 children between the ages of 3 and 18 years.

Along with previous studies that have also linked AD to depression and other mental health issues in children, these data highlight the need for “clinical awareness of the psychosocial needs of children and adolescents with AD,” reported a multicenter team of investigators from the University of California, San Francisco, the University of Pennsylvania, and the London School of Hygiene and Tropical Medicine.

Unlike some previous studies, in this study, published online in JAMA Dermatology on Sept. 1, children were evaluated longitudinally, rather than at a single point in time, with a mean follow-up of 10 years. For those with active AD, compared with children without AD, the odds ratio for depression overall in any child with AD relative to those without AD was not significant after adjustment for variables such socioeconomic factors.

However, among children with severe AD, the risk was more than twofold greater even after adjustment (adjusted OR, 2.38; 95% confidence interval, 1.21- 4.72), reported the investigators, led by senior author Katrina Abuabara, MD, associate professor of dermatology and epidemiology at UCSF.
 

Internalizing symptoms seen with mild to severe AD

Internalizing behavior, which is closely linked to depression and describes a spectrum of inward-focusing activities, such as social withdrawal, was significantly more common in children with any degree of AD relative to those without AD: After adjustment, the risk climbed from a 29% increased risk in those with mild AD (aOR, 1.29; 95% CI, 1.06-1.57) to a more than 80% increased risk in children with moderate AD (aOR, 1.84; 95% CI, 1.40-2.41) and in children with severe AD (aOR, 1.90; 95% CI, 1.14-3.16).

In the study, depression was measured with the Short Moods and Feelings Questionnaire (SMFQ). Parental response to the Emotional Symptoms subscale of the Strength and Difficulties Questionnaire (SDQ) was used to measure internalizing behaviors.

The data were drawn from the Avon Longitudinal Study for Parents and Children (ALSPAC), a cohort that enrolled pregnant women in a defined area in southwest England and then followed children born from these pregnancies. Of the 14,062 children enrolled in ALSPAC, data from 11,181 children were available for this study.

In a previous meta-analysis of studies that have documented a link between AD and adverse effects on mood and mental health, an impact was identified in both children and adults. In children, AD was associated with a 27% increase in risk of depression (OR, 1.27; 95% CI, 1.12 -1.45). In adults, the risk was more than doubled (OR, 2.19; 95% CI, 1.87-2.57). The same meta-analysis found that the risk of suicidal ideation among adolescents and adults with AD was increased more than fourfold (OR, 4.32; 95% CI, 1.93-9.66).

In the ALSPAC data, the investigators were unable to find compelling evidence that sleep disturbances or concomitant asthma contributed to the increased risk of depression, which is a mechanism proposed by past investigators.

In an interview, Dr. Abuabara said that these and other data provide the basis for encouraging clinical awareness of the psychological needs of children with AD, but she suggested there is a gap in understanding what this means clinically. “We need more data on how dermatologists can effectively screen and manage these patients before we try to set expectations for clinical practice,” she said.

In addition, these data along with previously published studies suggest that change in mental health outcomes should be included in the evaluation of new therapies, according to Dr. Abuabara. She noted that there are several tools for evaluating mental health in children that might be appropriate, each with their own advantages and disadvantages.

“Ideally, recommendations would be issued through a group consensus process with patients, clinicians, researchers, and industry representatives working together as has been done for other outcomes through the Harmonizing Measures for Eczema (HOME) group,” Dr. Abuabara said.

 

Mental health assessments recommended

Others who have looked at the relationship between AD and depression have also recommended adding mental health outcomes to an assessment of efficacy for AD therapies.

Jonathan I. Silverberg, MD, PhD, MPH, associate professor of dermatology, George Washington University, Washington, is one such investigator. He is already monitoring depression systematically with the Hospital Anxiety and Depression Scale (HADS).

“HADS has been validated in AD and provides very important information about the emotional burden of AD,” explained Dr. Silverberg, whose most recent article on this topic appeared earlier this year. In that study, the relationship between AD and depression was found to be more pronounced in White children from families with lower incomes.

“Just a few hours ago, one of my patients thanked me for asking about their mental health and recognizing the holistic effects of AD,” Dr. Silverberg said.

The recent study based on ALSPAC data add to the evidence that AD, particularly severe AD, produces deleterious effects on mental health in children, and Dr. Silverberg believes clinicians should be acting on this evidence.

“I strongly encourage clinicians to routinely assess mental health. It will elevate the quality of care they provide, and their patients will appreciate them more for it,” he said.

Dr. Abuabara and another author report receiving research funding from Pfizer to their universities for unrelated work; there were no other disclosures. Dr. Silverberg reports financial relationships with more than 15 pharmaceutical companies.

Commentary by Lawrence F. Eichenfield, MD

More severe atopic dermatitis (AD) carries with it significant mental health concerns in children, as well as adults. Multiple studies have shown significantly higher rates of depression, anxiety, and “internalizing behaviors” (discussed as social withdrawal and other inward-focused activities) as well as attention-deficit/hyperactivity disorder. The study by Dr. Abuabara and colleagues is important as it followed children over time (an average of 10 years) and adjusted the data for socioeconomic factors, showing a rate of depression in children with severe AD twice that of those without. It appears that we are in the midst of a mental health crisis in children and teens, with markedly higher rates of pediatric and adolescent depression and anxiety, certainly influenced by COVID-19 societal changes. As the literature has developed on depression and AD, we have appreciated the importance of addressing this as part of our assessment of the disease effect on the individual and family, and it is one factor we consider in selections of systemic vs. topical therapies.  

Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children's Hospital-San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. He disclosed that he has served as an investigator and/or consultant to AbbVie, Lilly, Pfizer, Regeneron, Sanofi-Genzyme, and Verrica.

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

This article was updated 6/18/22.

With more than 300 genetic skin disorders involving more than 1,000 genes and hundreds of genetic tests available on the market, it can be daunting for health care providers and families of pediatric patients to navigate the landscape.

“Testing options range from targeted variant testing and single-gene testing to exome and genome sequencing,” Gabriele Richard, MD, said at the annual meeting of the Society for Pediatric Dermatology. “It is not always easy to determine which testing is right.”

Increasingly, clinical genomic tests, including exome and genome sequencing, are used for patients with complex phenotypes, and possibly multiple disorders, who might have no diagnosis despite extensive prior testing, said Dr. Richard, medical director at Gaithersburg, Md.–based GeneDx., a molecular diagnostic laboratory that performs comprehensive testing for rare genetic disorders. These tests are also being used more for first-line testing in critically ill patients in the neonatal and pediatric intensive care units, and “have heralded a whole new era of gene and disease discovery,” she added.

Targeted variant testing is used for known familial variants, to test family members for carrier status and segregation, and to make a prenatal diagnosis, she said. Single-gene testing is available for most genes and has its place for conditions that can be clinically well-recognized, such as ichthyosis vulgaris, Darier disease, or Papillon-Lefèvre syndrome.

Specific tests for identifying gene deletions or duplications are exon-level microarrays, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray analysis. “The latter has been successful in identifying diseases causing chromosomal abnormalities in over 10% of cases overall,” Dr. Richard said. An example of a skin disorder is X-linked ichthyosis caused by a deletion of the steroid sulfatase locus in more than 95% of affected males, she said.

“However, the current staple of molecular diagnostic testing is multigene next-generation sequencing (NGS) panels, which allow you to interrogate two to hundreds of genes concurrently, including sequencing and deletion duplication testing.” These tests are the most cost effective, she said, and are available for almost any genodermatosis or group of disorders with overlapping phenotypes, such as albinism or ichthyosis, epidermolysis bullosa and skin fragility, ectodermal dysplasia, or porphyria. According to Dr. Richard, the diagnostic outcomes of NGS panels mainly depend on test indication, panel size and gene curation, age of onset, and prevailing inheritance pattern of disorders.

Her recommended criteria for distinguishing the myriad of available NGS panels include checking gene content, technical sensitivity of sequencing and deletion/duplication analysis, quality of variant interpretation and reporting, turn-around time, and available familial follow-up testing. “If a family might consider future prenatal diagnosis, choose the lab that performs prenatal and diagnostic testing,” Dr. Richard said. “Equally important are client services such as ease of ordering, insurance coverage, and the ability to determine out-of-pocket cost to patients.”

Resources that enable consumers to compare panel content, methodology, turnaround time, and other parameters include the Genetic Testing Registry (GTR) operated by the National Center for Biotechnology Information, and Concert Genetics, a genetic testing company. The National Society of Genetic Counselors also offers a searchable database for finding a genetic counselor.

Exome sequencing includes the coding sequences of about 20,000 genes and has an average depth of 50 to about 150 reads. “It is a phenotype-driven test where only select variants are being reported fitting the phenotype,” Dr. Richard said. “The outcome of exome and genome sequencing much depends on optimization of bioinformatic pipelines and tools.” Besides small sequence variants, exome sequencing is able to identify a variety of different types of disease-causing variants, such as gene copy number variants seen in about 6% of positive cases, mosaicism, regions of homozygosity, uniparental disomy, and other unusual events and is cost effective.

Whole-genome sequencing, meanwhile, includes the entire genome, particularly noncoding regions, and has an average depth of more than 30 reads. “It’s based on single-molecule sequencing, has longer reads and more uniform coverage, compared to exome sequencing,” she said. “Higher cost, variant interpretation, and lack of coverage by payers are still presenting challenges for genome sequencing.” Genome sequencing can be done in a day or less.

According to diagnostic outcomes based on 280,000 individuals including 125,000 probands from GeneDx data, a definitive diagnosis was made in 26% of probands, of which 2.8% had more than one diagnostic finding and 1.8% had actionable secondary findings. In addition, 7% of the variants were found in candidate genes; 31% of probands had variants of uncertain significance, while 36% tested negative. “Nevertheless, the diagnostic yield of exome sequencing depends on the phenotype and cohort studied,” Dr. Richard continued.

At her company, she said, the highest positive rate is for multiple congenital anomalies (34%), skeletal system abnormalities (30%), and nervous system abnormalities (29%). Trio testing – the concurrent analysis of both biological parents and proband for all genes – “is a critical factor for success,” she added. “It not only improves the variant calling because we have three times the data and increases test sensitivity, it also provides more certain results, determines inheritance and allows for detection of parental mosaicism.”

According to Dr. Richard, trio testing has a one-third higher diagnostic rate than sequencing of the proband alone. Citing a published prospective study that compiled data from eight different exome- and genome-sequencing studies in critically ill neonates and children, trio testing made it possible to make a genetic diagnosis in up to 58% of children.

Whole-genome sequencing is estimated to have a 5%-10% higher diagnostic rate than exome sequencing. “However, we are still a ways away from using it as a routine diagnostic test for all test indications,” Dr. Richard said. “Automation, special bioinformatics algorithms and databases, and combination of genome sequencing with mRNA sequencing are being explored and built to further improve the diagnostic yield.”

Dr. Richard had no disclosures other than being an employee of GeneDx.

[email protected]

With more than 300 genetic skin disorders involving more than 1,000 genes and hundreds of genetic tests available on the market, it can be daunting for health care providers and families of pediatric patients to navigate the landscape.

“Testing options range from targeted variant testing and single-gene testing to exome and genome sequencing,” Gabriele Richard, MD, said at the annual meeting of the Society for Pediatric Dermatology. “It is not always easy to determine which testing is right.”

Increasingly, clinical genomic tests, including exome and genome sequencing, are used for patients with complex phenotypes, and possibly multiple disorders, who might have no diagnosis despite extensive prior testing, said Dr. Richard, medical director at Gaithersburg, Md.–based GeneDx., a molecular diagnostic laboratory that performs comprehensive testing for rare genetic disorders. These tests are also being used more for first-line testing in critically ill patients in the neonatal and pediatric intensive care units, and “have heralded a whole new era of gene and disease discovery,” she added.

Targeted variant testing is used for known familial variants, to test family members for carrier status and segregation, and to make a prenatal diagnosis, she said. Single-gene testing is available for most genes and has its place for conditions that can be clinically well-recognized, such as ichthyosis vulgaris, Darier disease, or Papillon-Lefèvre syndrome.

Specific tests for identifying gene deletions or duplications are exon-level microarrays, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray analysis. “The latter has been successful in identifying diseases causing chromosomal abnormalities in over 10% of cases overall,” Dr. Richard said. An example of a skin disorder is X-linked ichthyosis caused by a deletion of the steroid sulfatase locus in more than 95% of affected males, she said.

“However, the current staple of molecular diagnostic testing is multigene next-generation sequencing (NGS) panels, which allow you to interrogate two to hundreds of genes concurrently, including sequencing and deletion duplication testing.” These tests are the most cost effective, she said, and are available for almost any genodermatosis or group of disorders with overlapping phenotypes, such as albinism or ichthyosis, epidermolysis bullosa and skin fragility, ectodermal dysplasia, or porphyria. According to Dr. Richard, the diagnostic outcomes of NGS panels mainly depend on test indication, panel size and gene curation, age of onset, and prevailing inheritance pattern of disorders.

Her recommended criteria for distinguishing the myriad of available NGS panels include checking gene content, technical sensitivity of sequencing and deletion/duplication analysis, quality of variant interpretation and reporting, turn-around time, and available familial follow-up testing. “If a family might consider future prenatal diagnosis, choose the lab that performs prenatal and diagnostic testing,” Dr. Richard said. “Equally important are client services such as ease of ordering, insurance coverage, and the ability to determine out-of-pocket cost to patients.”

Resources that enable consumers to compare panel content, methodology, turnaround time, and other parameters include the Genetic Testing Registry (GTR) operated by the National Center for Biotechnology Information, and Concert Genetics, a genetic testing company. The National Society of Genetic Counselors also offers a searchable database for finding a genetic counselor.

Exome sequencing includes the coding sequences of about 20,000 genes and has an average depth of 50 to about 150 reads. “It is a phenotype-driven test where only select variants are being reported fitting the phenotype,” Dr. Richard said. “The outcome of exome and genome sequencing much depends on optimization of bioinformatic pipelines and tools.” Besides small sequence variants, exome sequencing is able to identify a variety of different types of disease-causing variants, such as gene copy number variants seen in about 6% of positive cases, mosaicism, regions of homozygosity, uniparental disomy, and other unusual events and is cost effective.

Whole-genome sequencing, meanwhile, includes the entire genome, particularly noncoding regions, and has an average depth of more than 30 reads. “It’s based on single-molecule sequencing, has longer reads and more uniform coverage, compared to exome sequencing,” she said. “Higher cost, variant interpretation, and lack of coverage by payers are still presenting challenges for genome sequencing.” Genome sequencing can be done in a day or less.

According to diagnostic outcomes based on 280,000 individuals including 125,000 probands from GeneDx data, a definitive diagnosis was made in 26% of probands, of which 2.8% had more than one diagnostic finding and 1.8% had actionable secondary findings. In addition, 7% of the variants were found in candidate genes; 31% of probands had variants of uncertain significance, while 36% tested negative. “Nevertheless, the diagnostic yield of exome sequencing depends on the phenotype and cohort studied,” Dr. Richard continued.

At her company, she said, the highest positive rate is for multiple congenital anomalies (34%), skeletal system abnormalities (30%), and nervous system abnormalities (29%). Trio testing – the concurrent analysis of both biological parents and proband for all genes – “is a critical factor for success,” she added. “It not only improves the variant calling because we have three times the data and increases test sensitivity, it also provides more certain results, determines inheritance and allows for detection of parental mosaicism.”

According to Dr. Richard, trio testing has a one-third higher diagnostic rate than sequencing of the proband alone. Citing a published prospective study that compiled data from eight different exome- and genome-sequencing studies in critically ill neonates and children, trio testing made it possible to make a genetic diagnosis in up to 58% of children.

Whole-genome sequencing is estimated to have a 5%-10% higher diagnostic rate than exome sequencing. “However, we are still a ways away from using it as a routine diagnostic test for all test indications,” Dr. Richard said. “Automation, special bioinformatics algorithms and databases, and combination of genome sequencing with mRNA sequencing are being explored and built to further improve the diagnostic yield.”

Dr. Richard had no disclosures other than being an employee of GeneDx.

[email protected]

With more than 300 genetic skin disorders involving more than 1,000 genes and hundreds of genetic tests available on the market, it can be daunting for health care providers and families of pediatric patients to navigate the landscape.

“Testing options range from targeted variant testing and single-gene testing to exome and genome sequencing,” Gabriele Richard, MD, said at the annual meeting of the Society for Pediatric Dermatology. “It is not always easy to determine which testing is right.”

Increasingly, clinical genomic tests, including exome and genome sequencing, are used for patients with complex phenotypes, and possibly multiple disorders, who might have no diagnosis despite extensive prior testing, said Dr. Richard, medical director at Gaithersburg, Md.–based GeneDx., a molecular diagnostic laboratory that performs comprehensive testing for rare genetic disorders. These tests are also being used more for first-line testing in critically ill patients in the neonatal and pediatric intensive care units, and “have heralded a whole new era of gene and disease discovery,” she added.

Targeted variant testing is used for known familial variants, to test family members for carrier status and segregation, and to make a prenatal diagnosis, she said. Single-gene testing is available for most genes and has its place for conditions that can be clinically well-recognized, such as ichthyosis vulgaris, Darier disease, or Papillon-Lefèvre syndrome.

Specific tests for identifying gene deletions or duplications are exon-level microarrays, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray analysis. “The latter has been successful in identifying diseases causing chromosomal abnormalities in over 10% of cases overall,” Dr. Richard said. An example of a skin disorder is X-linked ichthyosis caused by a deletion of the steroid sulfatase locus in more than 95% of affected males, she said.

“However, the current staple of molecular diagnostic testing is multigene next-generation sequencing (NGS) panels, which allow you to interrogate two to hundreds of genes concurrently, including sequencing and deletion duplication testing.” These tests are the most cost effective, she said, and are available for almost any genodermatosis or group of disorders with overlapping phenotypes, such as albinism or ichthyosis, epidermolysis bullosa and skin fragility, ectodermal dysplasia, or porphyria. According to Dr. Richard, the diagnostic outcomes of NGS panels mainly depend on test indication, panel size and gene curation, age of onset, and prevailing inheritance pattern of disorders.

Her recommended criteria for distinguishing the myriad of available NGS panels include checking gene content, technical sensitivity of sequencing and deletion/duplication analysis, quality of variant interpretation and reporting, turn-around time, and available familial follow-up testing. “If a family might consider future prenatal diagnosis, choose the lab that performs prenatal and diagnostic testing,” Dr. Richard said. “Equally important are client services such as ease of ordering, insurance coverage, and the ability to determine out-of-pocket cost to patients.”

Resources that enable consumers to compare panel content, methodology, turnaround time, and other parameters include the Genetic Testing Registry (GTR) operated by the National Center for Biotechnology Information, and Concert Genetics, a genetic testing company. The National Society of Genetic Counselors also offers a searchable database for finding a genetic counselor.

Exome sequencing includes the coding sequences of about 20,000 genes and has an average depth of 50 to about 150 reads. “It is a phenotype-driven test where only select variants are being reported fitting the phenotype,” Dr. Richard said. “The outcome of exome and genome sequencing much depends on optimization of bioinformatic pipelines and tools.” Besides small sequence variants, exome sequencing is able to identify a variety of different types of disease-causing variants, such as gene copy number variants seen in about 6% of positive cases, mosaicism, regions of homozygosity, uniparental disomy, and other unusual events and is cost effective.

Whole-genome sequencing, meanwhile, includes the entire genome, particularly noncoding regions, and has an average depth of more than 30 reads. “It’s based on single-molecule sequencing, has longer reads and more uniform coverage, compared to exome sequencing,” she said. “Higher cost, variant interpretation, and lack of coverage by payers are still presenting challenges for genome sequencing.” Genome sequencing can be done in a day or less.

According to diagnostic outcomes based on 280,000 individuals including 125,000 probands from GeneDx data, a definitive diagnosis was made in 26% of probands, of which 2.8% had more than one diagnostic finding and 1.8% had actionable secondary findings. In addition, 7% of the variants were found in candidate genes; 31% of probands had variants of uncertain significance, while 36% tested negative. “Nevertheless, the diagnostic yield of exome sequencing depends on the phenotype and cohort studied,” Dr. Richard continued.

At her company, she said, the highest positive rate is for multiple congenital anomalies (34%), skeletal system abnormalities (30%), and nervous system abnormalities (29%). Trio testing – the concurrent analysis of both biological parents and proband for all genes – “is a critical factor for success,” she added. “It not only improves the variant calling because we have three times the data and increases test sensitivity, it also provides more certain results, determines inheritance and allows for detection of parental mosaicism.”

According to Dr. Richard, trio testing has a one-third higher diagnostic rate than sequencing of the proband alone. Citing a published prospective study that compiled data from eight different exome- and genome-sequencing studies in critically ill neonates and children, trio testing made it possible to make a genetic diagnosis in up to 58% of children.

Whole-genome sequencing is estimated to have a 5%-10% higher diagnostic rate than exome sequencing. “However, we are still a ways away from using it as a routine diagnostic test for all test indications,” Dr. Richard said. “Automation, special bioinformatics algorithms and databases, and combination of genome sequencing with mRNA sequencing are being explored and built to further improve the diagnostic yield.”

Dr. Richard had no disclosures other than being an employee of GeneDx.

[email protected]

Autoeczematization (AE), or id reaction, is a disseminated eczematous reaction that occurs days or weeks after exposure to a primary stimulus, resulting from a release of antigen(s). Whitfield¹ first described AE in 1921, when he postulated that the id reaction was due to sensitization of the skin after a primary stimulus. He called it “a form of auto-intoxication derived from changes in the patient’s own tissues.”¹ The exact prevalence of id reactions is unknown; one study showed that 17% of patients with dermatophyte infections developed an id reaction, typically tinea pedis linked with vesicles on the palms.² Tinea capitis is one of the most common causes of AE in children, which is frequently misdiagnosed as a drug reaction. Approximately 37% of patients diagnosed with stasis dermatitis develop an id reaction (Figure 1). A history of contact dermatitis is common in patients presenting with AE.^2-6

Pathophysiology of Id Reactions

An abnormal immune response against autologous skin antigens may be responsible for the development of AE. Shelley⁵ postulated that hair follicles play an important role in id reactions, as Sharquie et al⁶ recently emphasized for many skin disorders. The pathogenesis of AE is uncertain, but circulating T lymphocytes play a role in this reaction. Normally, T cells are activated by a release of antigens after a primary exposure to a stimulus. However, overactivation of these T cells induces autoimmune reactions such as AE.⁷ Activated T lymphocytes express HLA-DR and IL-2 receptor, markers elevated in the peripheral blood of patients undergoing id reactions. After treatment, the levels of activated T lymphocytes decline. An increase in the number of CD25⁺ T cells and a decrease in the number of suppressor T cells in the blood may occur during an id reaction.^7-9 Keratinocytes produce proinflammatory cytokines, such as thymic stromal erythropoietin, IL-25, and IL-33, that activate T cells.^10-12 Therefore, the most likely pathogenesis of an id reaction is that T lymphocytes are activated at the primary reaction site due to proinflammatory cytokines released by keratinocytes. These activated T cells then travel systemically via hematogenous dissemination. The spread of activated T lymphocytes produces an eczematous reaction at secondary locations distant to the primary site.⁹

Clinical and Histopathological Features of Id Reactions

Clinically, AE is first evident as a vesicular dissemination that groups to form papules or nummular patches and usually is present on the legs, feet, arms, and/or trunk (Figure 2). The primary dermatitis is localized to the area that was the site of contact to the offending stimuli. This localized eczematous eruption begins with an acute or subacute onset. It has the appearance of small crusted vesicles with erythema (Figure 1). The first sign of AE is vesicles presenting near the primary site on flexural surfaces or on the hands and feet. A classic example is tinea pedis linked with vesicles on the palms and sides of the fingers, resembling dyshidrotic eczema. Sites of prior cutaneous trauma, such as dermatoses, scars, and burns, are common locations for early AE. In later stages, vesicles disseminate to the legs, arms, and trunk, where they group to form papules and nummular patches in a symmetrical pattern.^5,13-15 These lesions may be extremely pruritic. The pruritus may be so intense that it interrupts daily activities and disrupts the ability to fall or stay asleep.¹⁶

Histologically, biopsy specimens show psoriasiform spongiotic dermatitis with mononuclear cells contained in the vesicles. Interstitial edema and perivascular lymphohistiocytic infiltrates are evident. Eosinophils also may be present. This pattern is not unique toid reactions.^17-19 Although AE is a reaction pattern that may be due to a fungal or bacterial infection, the etiologic agent is not evident microscopically within the eczema itself.

Etiology of Id Reactions

Id reactions most commonly occur from either stasis dermatitis or tinea pedis, although a wide variety of other causes should be considered. Evaluation of the primary site rather than the id reaction may identify an infectious or parasitic agent. Sometimes the AE reaction is specifically named: dermatophytid with dermatophytosis, bacterid with a bacterial infectious process, and tuberculid with tuberculosis. Similarly, there may be reactions to underlying candidiasis, sporotrichosis, histoplasmosis, and other fungal infections that can cause a cutaneous id reaction.^18,20-22Mycobacterium species, Pseudomonas, Staphylococcus, and Streptococcus are bacterial causes of AE.^15,23-26 Viral infections that can cause an id reaction are herpes simplex virus and molluscum contagiosum.^27-29 Scabies, leishmaniasis, and pediculosis capitis are parasitic infections that may be etiologic.^14,30,31 In addition, noninfectious stimuli besides stasis dermatitis that can produce id reactions include medications, topical creams, tattoo ink, sutures, radiotherapy, and dyshidrotic eczema. The primary reaction to these agents is a localized dermatitis followed by the immunological response that induces a secondary reaction distant from the primary site.^17,18,32-38

Differential Diagnoses

Differential diagnoses include other types of eczema and some vesicular eruptions. Irritant contact dermatitis is another dermatosis that presents as a widespread vesicular eruption due to repetitive exposure to toxic irritants. The rash is erythematous with pustules, blisters, and crusts. It is only found in areas directly exposed to irritants, as opposed to AE, which spreads to areas distant to the primary reaction site. Irritant contact dermatitis presents with more of a burning sensation, whereas AE is more pruritic.^39,40 Allergic contact dermatitis presents with erythematous vesicles and papules and sometimes with bullae. There is edema and crust formation, which often can spread past the point of contact in later stages. Similar to AE, there is intense pruritus. However, allergic contact dermatitis most commonly is caused by exposure to metals, cosmetics, and fragrances, whereas infectious agents and stasis dermatitis are the most common causes of AE.^40,41 It may be challenging to distinguish AE from other causes of widespread eczematous dissemination. Vesicular eruptions sometimes require distinction from AE, including herpetic infections, insect bite reactions, and drug eruptions.^18,42

Treatment

The underlying condition should be treated to mitigate the inflammatory response causing the id reaction. If not skillfully orchestrated, the id reaction can reoccur. For infectious causes of AE, an antifungal, antibacterial, antiviral, or antiparasitic should be given. If stasis dermatitis is responsible for the id reaction, compression stockings and leg elevation are indicated. The id reaction itself is treated with systemic or topical corticosteroids and wet compresses if acute. The goal of these treatments is to reduce patient discomfort caused by the inflammation and pruritus.^18,43

Conclusion

Id reactions are an unusual phenomenon that commonly occurs after fungal skin infections and stasis dermatitis. T lymphocytes and keratinocytes may play a key role in this reaction, with newer research further delineating the process and possibly providing enhanced treatment options. Therapy focuses on treating the underlying condition, supplemented with corticosteroids for the autoeczema.

Autoeczematization (AE), or id reaction, is a disseminated eczematous reaction that occurs days or weeks after exposure to a primary stimulus, resulting from a release of antigen(s). Whitfield¹ first described AE in 1921, when he postulated that the id reaction was due to sensitization of the skin after a primary stimulus. He called it “a form of auto-intoxication derived from changes in the patient’s own tissues.”¹ The exact prevalence of id reactions is unknown; one study showed that 17% of patients with dermatophyte infections developed an id reaction, typically tinea pedis linked with vesicles on the palms.² Tinea capitis is one of the most common causes of AE in children, which is frequently misdiagnosed as a drug reaction. Approximately 37% of patients diagnosed with stasis dermatitis develop an id reaction (Figure 1). A history of contact dermatitis is common in patients presenting with AE.^2-6

Pathophysiology of Id Reactions

An abnormal immune response against autologous skin antigens may be responsible for the development of AE. Shelley⁵ postulated that hair follicles play an important role in id reactions, as Sharquie et al⁶ recently emphasized for many skin disorders. The pathogenesis of AE is uncertain, but circulating T lymphocytes play a role in this reaction. Normally, T cells are activated by a release of antigens after a primary exposure to a stimulus. However, overactivation of these T cells induces autoimmune reactions such as AE.⁷ Activated T lymphocytes express HLA-DR and IL-2 receptor, markers elevated in the peripheral blood of patients undergoing id reactions. After treatment, the levels of activated T lymphocytes decline. An increase in the number of CD25⁺ T cells and a decrease in the number of suppressor T cells in the blood may occur during an id reaction.^7-9 Keratinocytes produce proinflammatory cytokines, such as thymic stromal erythropoietin, IL-25, and IL-33, that activate T cells.^10-12 Therefore, the most likely pathogenesis of an id reaction is that T lymphocytes are activated at the primary reaction site due to proinflammatory cytokines released by keratinocytes. These activated T cells then travel systemically via hematogenous dissemination. The spread of activated T lymphocytes produces an eczematous reaction at secondary locations distant to the primary site.⁹

Clinical and Histopathological Features of Id Reactions

Clinically, AE is first evident as a vesicular dissemination that groups to form papules or nummular patches and usually is present on the legs, feet, arms, and/or trunk (Figure 2). The primary dermatitis is localized to the area that was the site of contact to the offending stimuli. This localized eczematous eruption begins with an acute or subacute onset. It has the appearance of small crusted vesicles with erythema (Figure 1). The first sign of AE is vesicles presenting near the primary site on flexural surfaces or on the hands and feet. A classic example is tinea pedis linked with vesicles on the palms and sides of the fingers, resembling dyshidrotic eczema. Sites of prior cutaneous trauma, such as dermatoses, scars, and burns, are common locations for early AE. In later stages, vesicles disseminate to the legs, arms, and trunk, where they group to form papules and nummular patches in a symmetrical pattern.^5,13-15 These lesions may be extremely pruritic. The pruritus may be so intense that it interrupts daily activities and disrupts the ability to fall or stay asleep.¹⁶

Histologically, biopsy specimens show psoriasiform spongiotic dermatitis with mononuclear cells contained in the vesicles. Interstitial edema and perivascular lymphohistiocytic infiltrates are evident. Eosinophils also may be present. This pattern is not unique toid reactions.^17-19 Although AE is a reaction pattern that may be due to a fungal or bacterial infection, the etiologic agent is not evident microscopically within the eczema itself.

Etiology of Id Reactions

Id reactions most commonly occur from either stasis dermatitis or tinea pedis, although a wide variety of other causes should be considered. Evaluation of the primary site rather than the id reaction may identify an infectious or parasitic agent. Sometimes the AE reaction is specifically named: dermatophytid with dermatophytosis, bacterid with a bacterial infectious process, and tuberculid with tuberculosis. Similarly, there may be reactions to underlying candidiasis, sporotrichosis, histoplasmosis, and other fungal infections that can cause a cutaneous id reaction.^18,20-22Mycobacterium species, Pseudomonas, Staphylococcus, and Streptococcus are bacterial causes of AE.^15,23-26 Viral infections that can cause an id reaction are herpes simplex virus and molluscum contagiosum.^27-29 Scabies, leishmaniasis, and pediculosis capitis are parasitic infections that may be etiologic.^14,30,31 In addition, noninfectious stimuli besides stasis dermatitis that can produce id reactions include medications, topical creams, tattoo ink, sutures, radiotherapy, and dyshidrotic eczema. The primary reaction to these agents is a localized dermatitis followed by the immunological response that induces a secondary reaction distant from the primary site.^17,18,32-38

Differential Diagnoses

Differential diagnoses include other types of eczema and some vesicular eruptions. Irritant contact dermatitis is another dermatosis that presents as a widespread vesicular eruption due to repetitive exposure to toxic irritants. The rash is erythematous with pustules, blisters, and crusts. It is only found in areas directly exposed to irritants, as opposed to AE, which spreads to areas distant to the primary reaction site. Irritant contact dermatitis presents with more of a burning sensation, whereas AE is more pruritic.^39,40 Allergic contact dermatitis presents with erythematous vesicles and papules and sometimes with bullae. There is edema and crust formation, which often can spread past the point of contact in later stages. Similar to AE, there is intense pruritus. However, allergic contact dermatitis most commonly is caused by exposure to metals, cosmetics, and fragrances, whereas infectious agents and stasis dermatitis are the most common causes of AE.^40,41 It may be challenging to distinguish AE from other causes of widespread eczematous dissemination. Vesicular eruptions sometimes require distinction from AE, including herpetic infections, insect bite reactions, and drug eruptions.^18,42

Treatment

The underlying condition should be treated to mitigate the inflammatory response causing the id reaction. If not skillfully orchestrated, the id reaction can reoccur. For infectious causes of AE, an antifungal, antibacterial, antiviral, or antiparasitic should be given. If stasis dermatitis is responsible for the id reaction, compression stockings and leg elevation are indicated. The id reaction itself is treated with systemic or topical corticosteroids and wet compresses if acute. The goal of these treatments is to reduce patient discomfort caused by the inflammation and pruritus.^18,43

Conclusion

Id reactions are an unusual phenomenon that commonly occurs after fungal skin infections and stasis dermatitis. T lymphocytes and keratinocytes may play a key role in this reaction, with newer research further delineating the process and possibly providing enhanced treatment options. Therapy focuses on treating the underlying condition, supplemented with corticosteroids for the autoeczema.

Autoeczematization (AE), or id reaction, is a disseminated eczematous reaction that occurs days or weeks after exposure to a primary stimulus, resulting from a release of antigen(s). Whitfield¹ first described AE in 1921, when he postulated that the id reaction was due to sensitization of the skin after a primary stimulus. He called it “a form of auto-intoxication derived from changes in the patient’s own tissues.”¹ The exact prevalence of id reactions is unknown; one study showed that 17% of patients with dermatophyte infections developed an id reaction, typically tinea pedis linked with vesicles on the palms.² Tinea capitis is one of the most common causes of AE in children, which is frequently misdiagnosed as a drug reaction. Approximately 37% of patients diagnosed with stasis dermatitis develop an id reaction (Figure 1). A history of contact dermatitis is common in patients presenting with AE.^2-6

Pathophysiology of Id Reactions

An abnormal immune response against autologous skin antigens may be responsible for the development of AE. Shelley⁵ postulated that hair follicles play an important role in id reactions, as Sharquie et al⁶ recently emphasized for many skin disorders. The pathogenesis of AE is uncertain, but circulating T lymphocytes play a role in this reaction. Normally, T cells are activated by a release of antigens after a primary exposure to a stimulus. However, overactivation of these T cells induces autoimmune reactions such as AE.⁷ Activated T lymphocytes express HLA-DR and IL-2 receptor, markers elevated in the peripheral blood of patients undergoing id reactions. After treatment, the levels of activated T lymphocytes decline. An increase in the number of CD25⁺ T cells and a decrease in the number of suppressor T cells in the blood may occur during an id reaction.^7-9 Keratinocytes produce proinflammatory cytokines, such as thymic stromal erythropoietin, IL-25, and IL-33, that activate T cells.^10-12 Therefore, the most likely pathogenesis of an id reaction is that T lymphocytes are activated at the primary reaction site due to proinflammatory cytokines released by keratinocytes. These activated T cells then travel systemically via hematogenous dissemination. The spread of activated T lymphocytes produces an eczematous reaction at secondary locations distant to the primary site.⁹

Clinical and Histopathological Features of Id Reactions

Clinically, AE is first evident as a vesicular dissemination that groups to form papules or nummular patches and usually is present on the legs, feet, arms, and/or trunk (Figure 2). The primary dermatitis is localized to the area that was the site of contact to the offending stimuli. This localized eczematous eruption begins with an acute or subacute onset. It has the appearance of small crusted vesicles with erythema (Figure 1). The first sign of AE is vesicles presenting near the primary site on flexural surfaces or on the hands and feet. A classic example is tinea pedis linked with vesicles on the palms and sides of the fingers, resembling dyshidrotic eczema. Sites of prior cutaneous trauma, such as dermatoses, scars, and burns, are common locations for early AE. In later stages, vesicles disseminate to the legs, arms, and trunk, where they group to form papules and nummular patches in a symmetrical pattern.^5,13-15 These lesions may be extremely pruritic. The pruritus may be so intense that it interrupts daily activities and disrupts the ability to fall or stay asleep.¹⁶

Histologically, biopsy specimens show psoriasiform spongiotic dermatitis with mononuclear cells contained in the vesicles. Interstitial edema and perivascular lymphohistiocytic infiltrates are evident. Eosinophils also may be present. This pattern is not unique toid reactions.^17-19 Although AE is a reaction pattern that may be due to a fungal or bacterial infection, the etiologic agent is not evident microscopically within the eczema itself.

Etiology of Id Reactions

Id reactions most commonly occur from either stasis dermatitis or tinea pedis, although a wide variety of other causes should be considered. Evaluation of the primary site rather than the id reaction may identify an infectious or parasitic agent. Sometimes the AE reaction is specifically named: dermatophytid with dermatophytosis, bacterid with a bacterial infectious process, and tuberculid with tuberculosis. Similarly, there may be reactions to underlying candidiasis, sporotrichosis, histoplasmosis, and other fungal infections that can cause a cutaneous id reaction.^18,20-22Mycobacterium species, Pseudomonas, Staphylococcus, and Streptococcus are bacterial causes of AE.^15,23-26 Viral infections that can cause an id reaction are herpes simplex virus and molluscum contagiosum.^27-29 Scabies, leishmaniasis, and pediculosis capitis are parasitic infections that may be etiologic.^14,30,31 In addition, noninfectious stimuli besides stasis dermatitis that can produce id reactions include medications, topical creams, tattoo ink, sutures, radiotherapy, and dyshidrotic eczema. The primary reaction to these agents is a localized dermatitis followed by the immunological response that induces a secondary reaction distant from the primary site.^17,18,32-38

Differential Diagnoses

Differential diagnoses include other types of eczema and some vesicular eruptions. Irritant contact dermatitis is another dermatosis that presents as a widespread vesicular eruption due to repetitive exposure to toxic irritants. The rash is erythematous with pustules, blisters, and crusts. It is only found in areas directly exposed to irritants, as opposed to AE, which spreads to areas distant to the primary reaction site. Irritant contact dermatitis presents with more of a burning sensation, whereas AE is more pruritic.^39,40 Allergic contact dermatitis presents with erythematous vesicles and papules and sometimes with bullae. There is edema and crust formation, which often can spread past the point of contact in later stages. Similar to AE, there is intense pruritus. However, allergic contact dermatitis most commonly is caused by exposure to metals, cosmetics, and fragrances, whereas infectious agents and stasis dermatitis are the most common causes of AE.^40,41 It may be challenging to distinguish AE from other causes of widespread eczematous dissemination. Vesicular eruptions sometimes require distinction from AE, including herpetic infections, insect bite reactions, and drug eruptions.^18,42

Treatment

The underlying condition should be treated to mitigate the inflammatory response causing the id reaction. If not skillfully orchestrated, the id reaction can reoccur. For infectious causes of AE, an antifungal, antibacterial, antiviral, or antiparasitic should be given. If stasis dermatitis is responsible for the id reaction, compression stockings and leg elevation are indicated. The id reaction itself is treated with systemic or topical corticosteroids and wet compresses if acute. The goal of these treatments is to reduce patient discomfort caused by the inflammation and pruritus.^18,43

Conclusion

Id reactions are an unusual phenomenon that commonly occurs after fungal skin infections and stasis dermatitis. T lymphocytes and keratinocytes may play a key role in this reaction, with newer research further delineating the process and possibly providing enhanced treatment options. Therapy focuses on treating the underlying condition, supplemented with corticosteroids for the autoeczema.

To the Editor:

Oral immunosuppressive therapies are prescribed for moderate to severe atopic dermatitis. Patients often consult YouTube to make informed decisions about these therapies. In the United States, most health-related online searches are initiated through a search engine, which frequently leads to social media sites such as YouTube. Recent studies have examined the reasons why users turn to the Internet for health-related information, indicating that users typically seek specific information regarding health concerns.^1,2 Furthermore, social media platforms such as YouTube are a popular means of sharing health information with the public.^3-5 Currently, YouTube has more than 1 billion registered users, and 30 million health-related videos are watched each day.⁶ Almost one-third of US consumers use YouTube, Facebook, and Twitter to obtain medical information.⁷ YouTube is a versatile tool because of its video-discovery mechanisms such as a keyword-based search engine, video-recommendation system, highlight feature for videos on home pages, and the capacity to embed YouTube videos on various web pages.⁸ Searchers use videos that are short, fast paced, emotion evoking, from credible sources, recently uploaded, and relevant to the searcher for aiding in health decisions.⁹ Furthermore, studies have demonstrated YouTube’s capacity to support a change in attitude and increase users’ knowledge. In fact, YouTube had higher impact on recall, attitudes, and behaviors when compared with written materials on other social media platforms, such as Facebook and Twitter.⁹ We conducted a cross-sectional study to examine the quality of YouTube videos on oral therapies for atopic dermatitis, such as cyclosporine, methotrexate, azathioprine, and mycophenolate mofetil.

On April 23, 2020, we performed 8 searches using a private browser with default filters on YouTube (Figure). Injectables were not included in the analysis, as the YouTube experience on dupilumab previously has been investigated.¹⁰ The top 40 videos from each search were screened by 3 researchers. Duplicates, non–English-language videos, and videos that did not discuss atopic dermatitis or oral therapies were excluded, resulting in 73 videos included in this analysis. Testimonials generated by patients made up 39 of 73 (53.4%) videos. Health care professionals created 23 of 73 (31.5%) videos, and educators with financial interest created 11 of 73 (15.1%) videos. The dates of production for the videos spanned from 2008 to 2020.

Importantly, this analysis is limited by its lack of quality-assessment tools for video-based resources such as JAMA score and DISCERN score.^14,15 However, these metrics have limited ability to evaluate audiovisual elements, indicating the need for novel tools to score their validity.

To the Editor:

Oral immunosuppressive therapies are prescribed for moderate to severe atopic dermatitis. Patients often consult YouTube to make informed decisions about these therapies. In the United States, most health-related online searches are initiated through a search engine, which frequently leads to social media sites such as YouTube. Recent studies have examined the reasons why users turn to the Internet for health-related information, indicating that users typically seek specific information regarding health concerns.^1,2 Furthermore, social media platforms such as YouTube are a popular means of sharing health information with the public.^3-5 Currently, YouTube has more than 1 billion registered users, and 30 million health-related videos are watched each day.⁶ Almost one-third of US consumers use YouTube, Facebook, and Twitter to obtain medical information.⁷ YouTube is a versatile tool because of its video-discovery mechanisms such as a keyword-based search engine, video-recommendation system, highlight feature for videos on home pages, and the capacity to embed YouTube videos on various web pages.⁸ Searchers use videos that are short, fast paced, emotion evoking, from credible sources, recently uploaded, and relevant to the searcher for aiding in health decisions.⁹ Furthermore, studies have demonstrated YouTube’s capacity to support a change in attitude and increase users’ knowledge. In fact, YouTube had higher impact on recall, attitudes, and behaviors when compared with written materials on other social media platforms, such as Facebook and Twitter.⁹ We conducted a cross-sectional study to examine the quality of YouTube videos on oral therapies for atopic dermatitis, such as cyclosporine, methotrexate, azathioprine, and mycophenolate mofetil.

On April 23, 2020, we performed 8 searches using a private browser with default filters on YouTube (Figure). Injectables were not included in the analysis, as the YouTube experience on dupilumab previously has been investigated.¹⁰ The top 40 videos from each search were screened by 3 researchers. Duplicates, non–English-language videos, and videos that did not discuss atopic dermatitis or oral therapies were excluded, resulting in 73 videos included in this analysis. Testimonials generated by patients made up 39 of 73 (53.4%) videos. Health care professionals created 23 of 73 (31.5%) videos, and educators with financial interest created 11 of 73 (15.1%) videos. The dates of production for the videos spanned from 2008 to 2020.

Importantly, this analysis is limited by its lack of quality-assessment tools for video-based resources such as JAMA score and DISCERN score.^14,15 However, these metrics have limited ability to evaluate audiovisual elements, indicating the need for novel tools to score their validity.

To the Editor:

Oral immunosuppressive therapies are prescribed for moderate to severe atopic dermatitis. Patients often consult YouTube to make informed decisions about these therapies. In the United States, most health-related online searches are initiated through a search engine, which frequently leads to social media sites such as YouTube. Recent studies have examined the reasons why users turn to the Internet for health-related information, indicating that users typically seek specific information regarding health concerns.^1,2 Furthermore, social media platforms such as YouTube are a popular means of sharing health information with the public.^3-5 Currently, YouTube has more than 1 billion registered users, and 30 million health-related videos are watched each day.⁶ Almost one-third of US consumers use YouTube, Facebook, and Twitter to obtain medical information.⁷ YouTube is a versatile tool because of its video-discovery mechanisms such as a keyword-based search engine, video-recommendation system, highlight feature for videos on home pages, and the capacity to embed YouTube videos on various web pages.⁸ Searchers use videos that are short, fast paced, emotion evoking, from credible sources, recently uploaded, and relevant to the searcher for aiding in health decisions.⁹ Furthermore, studies have demonstrated YouTube’s capacity to support a change in attitude and increase users’ knowledge. In fact, YouTube had higher impact on recall, attitudes, and behaviors when compared with written materials on other social media platforms, such as Facebook and Twitter.⁹ We conducted a cross-sectional study to examine the quality of YouTube videos on oral therapies for atopic dermatitis, such as cyclosporine, methotrexate, azathioprine, and mycophenolate mofetil.

On April 23, 2020, we performed 8 searches using a private browser with default filters on YouTube (Figure). Injectables were not included in the analysis, as the YouTube experience on dupilumab previously has been investigated.¹⁰ The top 40 videos from each search were screened by 3 researchers. Duplicates, non–English-language videos, and videos that did not discuss atopic dermatitis or oral therapies were excluded, resulting in 73 videos included in this analysis. Testimonials generated by patients made up 39 of 73 (53.4%) videos. Health care professionals created 23 of 73 (31.5%) videos, and educators with financial interest created 11 of 73 (15.1%) videos. The dates of production for the videos spanned from 2008 to 2020.

Importantly, this analysis is limited by its lack of quality-assessment tools for video-based resources such as JAMA score and DISCERN score.^14,15 However, these metrics have limited ability to evaluate audiovisual elements, indicating the need for novel tools to score their validity.

To the Editor:

Atopic dermatitis (eczema) affects approximately 20% of children worldwide.¹ In atopic dermatitis management, patient education is crucial for optimal outcomes.² The COVID-19 pandemic has impacted patient-physician interactions. To ensure safety of patients and physicians, visits may have been canceled, postponed, or conducted virtually, leaving less time for discussion and questions.³ As a consequence, patients may seek information about atopic dermatitis from alternative sources, including YouTube videos. We performed a cross-sectional study to analyze YouTube videos about topical treatments for atopic dermatitis.

During the week of July 16, 2020, we performed 4 private browser YouTube searches with default filters using the following terms: eczema topicals, eczema topical treatments, atopic dermatitis topicals, and atopic dermatitis topical treatments. For video selection, we defined topical treatments as topical corticosteroids, topical calcineurin inhibitors, crisaborole, emollients, wet wraps, and any prospective treatment topically administered. For each of the 4 searches, 2 researchers (A.M. and A.T.) independently examined the top 75 videos, yielding a total of 300 videos. Of them, 98 videos were duplicates, 19 videos were not about atopic dermatitis, and 91 videos were not about topical treatments, leaving a total of 92 videos for analysis (Figure 1).

Although less popular, professional source videos had a significantly higher DISCERN overall quality rating score (question 16) compared to those categorized as nonprofessional source (3.92 vs 1.53; P<.001). In contrast, nonprofessional source videos scored significantly higher on the quality-of-life question (question 13) compared to professional source videos (3.90 vs 2.56; P<.001)(eTable). (Three professional source videos were removed from YouTube before DISCERN scores could be assigned.)

To the Editor:

Atopic dermatitis (eczema) affects approximately 20% of children worldwide.¹ In atopic dermatitis management, patient education is crucial for optimal outcomes.² The COVID-19 pandemic has impacted patient-physician interactions. To ensure safety of patients and physicians, visits may have been canceled, postponed, or conducted virtually, leaving less time for discussion and questions.³ As a consequence, patients may seek information about atopic dermatitis from alternative sources, including YouTube videos. We performed a cross-sectional study to analyze YouTube videos about topical treatments for atopic dermatitis.

During the week of July 16, 2020, we performed 4 private browser YouTube searches with default filters using the following terms: eczema topicals, eczema topical treatments, atopic dermatitis topicals, and atopic dermatitis topical treatments. For video selection, we defined topical treatments as topical corticosteroids, topical calcineurin inhibitors, crisaborole, emollients, wet wraps, and any prospective treatment topically administered. For each of the 4 searches, 2 researchers (A.M. and A.T.) independently examined the top 75 videos, yielding a total of 300 videos. Of them, 98 videos were duplicates, 19 videos were not about atopic dermatitis, and 91 videos were not about topical treatments, leaving a total of 92 videos for analysis (Figure 1).

Although less popular, professional source videos had a significantly higher DISCERN overall quality rating score (question 16) compared to those categorized as nonprofessional source (3.92 vs 1.53; P<.001). In contrast, nonprofessional source videos scored significantly higher on the quality-of-life question (question 13) compared to professional source videos (3.90 vs 2.56; P<.001)(eTable). (Three professional source videos were removed from YouTube before DISCERN scores could be assigned.)

To the Editor:

Atopic dermatitis (eczema) affects approximately 20% of children worldwide.¹ In atopic dermatitis management, patient education is crucial for optimal outcomes.² The COVID-19 pandemic has impacted patient-physician interactions. To ensure safety of patients and physicians, visits may have been canceled, postponed, or conducted virtually, leaving less time for discussion and questions.³ As a consequence, patients may seek information about atopic dermatitis from alternative sources, including YouTube videos. We performed a cross-sectional study to analyze YouTube videos about topical treatments for atopic dermatitis.

During the week of July 16, 2020, we performed 4 private browser YouTube searches with default filters using the following terms: eczema topicals, eczema topical treatments, atopic dermatitis topicals, and atopic dermatitis topical treatments. For video selection, we defined topical treatments as topical corticosteroids, topical calcineurin inhibitors, crisaborole, emollients, wet wraps, and any prospective treatment topically administered. For each of the 4 searches, 2 researchers (A.M. and A.T.) independently examined the top 75 videos, yielding a total of 300 videos. Of them, 98 videos were duplicates, 19 videos were not about atopic dermatitis, and 91 videos were not about topical treatments, leaving a total of 92 videos for analysis (Figure 1).

Although less popular, professional source videos had a significantly higher DISCERN overall quality rating score (question 16) compared to those categorized as nonprofessional source (3.92 vs 1.53; P<.001). In contrast, nonprofessional source videos scored significantly higher on the quality-of-life question (question 13) compared to professional source videos (3.90 vs 2.56; P<.001)(eTable). (Three professional source videos were removed from YouTube before DISCERN scores could be assigned.)

Plants can contribute to a variety of dermatoses. The Toxicodendron genus, which includes poison ivy, poison oak, and poison sumac, is a well-known and common cause of allergic contact dermatitis (ACD), but many other plants can cause direct or airborne contact dermatitis, especially in gardeners, florists, and farmers. This article provides an overview of different plant-related dermatoses and culprit plants as well as how these dermatoses should be diagnosed and treated.

Epidemiology

Plant dermatoses affect more than 50 million individuals each year.^1,2 In the United States, the Toxicodendron genus causes ACD in more than 70% of exposed individuals, leading to medical visits.³ An urgent care visit for a plant-related dermatitis is estimated to cost $168, while an emergency department visit can cost 3 times as much.⁴ Although less common, Compositae plants are another important culprit of plant dermatitis, particularly in gardeners, florists, and farmers. Data from the 2017-2018 North American Contact Dermatitis Group screening series (N=4947) showed sesquiterpene lactones and Compositae to be positive in 0.5% of patch-tested patients.⁵

Plant Dermatitis Classifications

Plant dermatitis can be classified into 5 main categories: ACD, mechanical irritant contact dermatitis, chemical irritant contact dermatitis, light-mediated dermatitis, and pseudophytodermatitis.⁶

Allergic contact dermatitis is an immune-mediated type IV delayed hypersensitivity reaction. The common molecular allergens in plants include phenols, α-methylene-γ-butyrolactones, quinones, terpenes, disulfides, isothiocyanates, and polyacetylenic derivatives.⁶

Plant contact dermatitis due to mechanical and chemical irritants is precipitated by multiple mechanisms, including disruption of the epidermal barrier and subsequent cytokine release from keratinocytes.⁷ Nonimmunologic contact urticaria from plants is thought to be a type of irritant reaction precipitated by mechanical or chemical trauma.⁸

Light-mediated dermatitis includes phytophotodermatitis and photoallergic contact dermatitis. Phytophotodermatitis is a phototoxic reaction triggered by exposure to both plant-derived furanocoumarin and UVA light.⁹ By contrast, photoallergic contact dermatitis is a delayed hypersensitivity reaction from prior sensitization to a light-activated antigen.¹⁰

Pseudophytodermatitis, as its name implies, is not truly mediated by an allergen or irritant intrinsic to the plant but rather by dyes, waxes, insecticides, or arthropods that inhabit the plant or are secondarily applied.⁶

Common Plant Allergens

Anacardiaceae Family
Most of the allergenic plants within the Anacardiaceae family belong to the Toxicodendron genus, which encompasses poison ivy (Toxicodendron radicans), poison oak (Toxicodendron pubescens,Toxicodendron quercifolium, Toxicodendron diversiloum), and poison sumac (Toxicodendron vernix). Poison ivy is the celebrity of the Anacardiaceae family and contributes to most cases of plant-related ACD. It is found in every state in the continental United States. Poison oak is another common culprit found in the western and southeastern United States.¹¹ Plants within the Anacardiaceae family contain an oleoresin called urushiol, which is the primary sensitizing substance. Although poison ivy and poison oak grow well in full sun to partial shade, poison sumac typically is found in damp swampy areas east of the Rocky Mountains. Most cases of ACD related to Anacardiaceae species are due to direct contact with urushiol from a Toxicodendron plant, but burning of brush containing Toxicodendron can cause airborne exposure when urushiol oil is carried by smoke particles.¹² Sensitization to Toxicodendron can cause ACD to other Anacardiaceae species such as the Japanese lacquer tree (Toxicodendron vernicifluum), mango tree (Mangifera indica), cashew tree (Anacardium occidentale), and Indian marking nut tree (Semecarpus anacardium).⁶ Cross-reactions to components of the ginkgo tree (Ginkgo biloba) also are possible.

Toxicodendron plants can be more easily identified and avoided with knowledge of their characteristic leaf patterns. The most dependable way to identify poison ivy and poison oak species is to look for plants with 3 leaves, giving rise to the common saying, “Leaves of three, leave them be.” Poison sumac plants have groups of 7 to 13 leaves arranged as pairs along a central rib. Another helpful finding is a black deposit that Toxicodendron species leave behind following trauma to the leaves. Urushiol oxidizes when exposed to air and turns into a black deposit that can be seen on damaged leaves themselves or can be demonstrated in a black spot test to verify if a plant is a Toxicodendron species. The test is performed by gathering (carefully, without direct contact) a few leaves in a paper towel and crushing them to release sap. Within minutes, the sap will turn black if the plant is indeed a Toxicodendron species.¹³Pruritic, edematous, erythematous papules, plaques, and eventual vesicles in a linear distribution are suspicious for Toxicodendron exposure. Although your pet will not develop Toxicodendron ACD, oleoresin-contaminated pets can transfer the oils to their owners after coming into contact with these plants. Toxicodendron dermatitis also can be acquired from oleoresin-contaminated fomites such as clothing and shoes worn in the garden or when hiking. Toxicodendron dermatitis can appear at different sites on the body at different times depending on the amount of oleoresin exposure as well as epidermal thickness. For example, the oleoresin can be transferred from the hands to body areas with a thinner stratum corneum (eg, genitalia) and cause subsequent dermatitis.¹

Compositae Family
The Compositae family (also known as Asteraceae) is a large plant family with more than 20,000 species, including numerous weeds, wildflowers, and vegetables. The flowers, leaves, stems, and pollens of the Compositae family are coated by cyclic esters called sesquiterpene lactones. Mitchell and Dupuis¹⁴ showed that sesquiterpene lactones are the allergens responsible for ACD to various Compositae plants, including ragweed (Ambrosia), sneezeweed (Helenium), and chrysanthemums (Chrysanthemum). Common Compositae vegetables such as lettuce (Lactuca sativa) have been reported to cause ACD in chefs, grocery store produce handlers, gardeners, and even owners of lettuce-eating pet guinea pigs and turtles.¹⁵ Similarly, artichokes (Cynara scolymus) can cause ACD in gardeners.¹⁶ Exposure to Compositae species also has been implicated in photoallergic reactions, and studies have demonstrated that some patients with chronic actinic dermatitis also have positive patch test reactions to Compositae species and/or sesquiterpene lactones.^17,18

In addition to direct contact with Compositae plants, airborne exposure to sesquiterpene lactones can cause ACD.¹⁴ The pattern of airborne contact dermatitis typically involves exposed areas such as the eyelids, central face, and/or neck. The beak sign also can be a clue to airborne contact dermatitis, which involves dermatitis of the face that spares the nasal tip and/or nasal ridge. It is thought that the beak sign may result from increased sebaceous gland concentration on the nose, which prevents penetration of allergens and irritants.¹⁹ Unlike photoallergic contact dermatitis, which also can involve the face, airborne ACD frequently involves photoprotected areas such as the submandibular chin and the upper lip. Davies and Kersey²⁰ reported the case of a groundsman who was cutting grass with dandelions (Taraxacum officinale) and was found to have associated airborne ACD of the face, neck, and forearms due to Compositae allergy. In a different setting, the aromas of chamomile (Matricaria chamomilla) have been reported to cause airborne ACD in a tea drinker.²¹ Paulsen²² found that ingestion of chamomile tea can induce systemic ACD in sensitized individuals.

Alstroemeriaceae, Liliaceae, and Primulaceae
Florists are exposed to many plant species and have a high prevalence of ACD. Thiboutot et al²³ found that 15 of 57 (26%) floral workers experienced hand dermatitis that cleared with time away from work. The Peruvian lily (Alstroemeria, Alstroemeriaceae family), which contains tuliposide A, was found to be the leading cause of sensitization.²³ Tulips (Tulipa, Liliaceae family), as the flower name suggests, also contain tuliposide A, which along with mechanical irritation from the course tecta fibers on the bulbs lead to a dermatitis known as tulip fingers.^24,25 Poison primrose (Primula obconica, Primulaceae family), cultivated for its highly colorful flowers, contains the contact allergen primin.⁶ A common clinical presentation of ACD for any of these culprit flowers is localized dermatitis of the thumb and index finger in a florist or gardener.

Plants That Cause Irritant Reactions

Cactuses
Although the long spines of the Cactaceae family of cactuses is a warning for passersby, it is the small and nearly invisible barbed hairs (glochids) that inflict a more dramatic cutaneous reaction. The prickly pear cactus (Opuntia species) is a good example of such a plant, as its glochids cause mechanical irritation but also can become embedded in the skin and result in subcutaneous granulomas known as sabra dermatitis.²⁶

Stinging Nettle
The dermatologic term urticaria owes its namesake to the stinging nettle plant, which comes from the family Urticaceae. The stinging nettle has small hairs on its leaves, referred to as stinging trichomes, which have needlelike tips that pierce the skin and inject a mix of histamine, formic acid, and acetylcholine, causing a pruritic dermatitis that may last up to 12 hours.²⁷ The plant is found worldwide and is a common weed in North America.

Phytophotodermatitis

Lemons and limes (Rutaceae family) are common culprits of phytophotodermatitis, often causing what is known as a margarita burn after outdoor consumption or preparation of this tasty citrus beverage.²⁸ An accidental spray of lime juice on the skin while adding it to a beer, guacamole, salsa, or any other food or beverage also can cause phytophotodermatitis.^29-31 Although the juice of lemons and limes contains psoralens, the rind can contain a 6- to 186-fold increased concentration.³² Psoralen is the photoactive agent in Rutaceae plants that intercalates in double-stranded DNA and promotes intrastrand cross-links when exposed to UVA light, which ultimately leads to dermatitis.⁹ Phytophotodermatitis commonly causes erythema, edema, and painful bullae on sun-exposed areas and classically heals with hyperpigmentation.

Pseudophytodermatitis can occur in grain farmers and harvesters who handle wheat and/or barley and incidentally come in contact with insects and chemicals on the plant material. Pseudophytodermatitis from mites in the wheat and/or barley plant can occur at harvest time when contact with the plant material is high. Insects such as the North American itch mite (Pediculoides ventricosus) can cause petechiae, wheals, and pustules. In addition, insecticides such as malathion and arsenical sprays that are applied to plant leaves can cause pseudophytodermatitis, which may be initially diagnosed as dermatitis to the plant itself.⁶

Patch Testing to Plants

When a patient presents with recurrent or persistent dermatitis and a plant contact allergen is suspected, patch testing is indicated. Most comprehensive patch test series contain various plant allergens, such as sesquiterpene lactones, Compositae mix, and limonene hydroperoxides, and patch testing to a specialized plant series may be necessary. Poison ivy/oak/sumac allergens typically are not included in patch test series because of the high prevalence of allergic reactions to these chemicals and the likelihood of sensitization when patch testing with urushiol. Compositae contact sensitization can be difficult to diagnose because neither sesquiterpene lactone mix 0.1% nor parthenolide 0.1% are sensitive enough to pick up all Compositae allergies.^33,34 Paulsen and Andersen³⁴ proposed that if Compositae sensitization is suspected, testing should include sesquiterpene lactone, parthenolide, and Compositae mix II 2.5%, as well as other potential Compositae allergens based on the patient’s history.³⁴

Because plants can have geographic variability and contain potentially unknown allergens,³⁵ testing to plant components may increase the diagnostic yield of patch testing. Dividing the plant into component parts (ie, stem, bulb, leaf, flower) is helpful, as different components have different allergen concentrations. It is important to consult expert resources before proceeding with plant component patch testing because irritant reactions are frequent and may confound the testing.³⁶

Prevention and Treatment

For all plant dermatoses, the mainstay of prevention is to avoid contact with the offending plant material. Gloves can be an important protective tool for plant dermatitis prevention; the correct material depends on the plant species being handled. Rubber gloves should not be worn to protect against Toxicodendron plants since the catechols in urushiol are soluble in rubber; vinyl gloves should be worn instead.⁶ Marks³⁷ found that tuliposide A, the allergen in the Peruvian lily (Alstroemeria), penetrates both vinyl and latex gloves; it does not penetrate nitrile gloves. If exposed, the risk of dermatitis can be decreased if the allergen is washed away with soap and water as soon as possible. Some allergens such as Toxicodendron are absorbed quickly and need to be washed off within 10 minutes of exposure.⁶ Importantly, exposed gardening gloves may continue to perpetuate ACD if the allergen is not also washed off the gloves themselves.

For light-mediated dermatoses, sun avoidance or use of an effective sunscreen can reduce symptoms in an individual who has already been exposed.¹⁰ UVA light activates psoralen-mediated dermatitis but not until 30 to 120 minutes after absorption into the skin.³⁸

Barrier creams are thought to be protective against plant ACD through a variety of mechanisms. The cream itself is meant to reduce skin contact to an allergen or irritant. Additionally, barrier creams contain active ingredients such as silicone, hydrocarbons, and aluminum chlorohydrate, which are thought to trap or transform offending agents before contacting the skin. When contact with a Toxicodendron species is anticipated, Marks et al³⁹ found that dermatitis was absent or significantly reduced when 144 patients were pretreated with quaternium-18 bentonite lotion 5% (P<.0001).

Although allergen avoidance and use of gloves and barrier creams are the mainstays of preventing plant dermatoses, treatment often is required to control postexposure symptoms. For all plant dermatoses, topical corticosteroids can be used to reduce inflammation and pruritus. In some cases, systemic steroids may be necessary. To prevent rebound of dermatitis, patients often require a 3-week or longer course of oral steroids to quell the reaction, particularly if the dermatitis is vigorous or an id reaction is present.⁴⁰ Antihistamines and cold compresses also can provide symptomatic relief.

Final Interpretation

Plants can cause a variety of dermatoses. Although Toxicodendron plants are the most frequent cause of ACD, it is important to keep in mind that florists, gardeners, and farmers are exposed to a large variety of allergens, irritants, and phototoxic agents that cause dermatoses as well. Confirmation of plant-induced ACD involves patch testing against suspected species. Prevention involves use of appropriate barriers and avoidance of implicated plants. Treatment includes topical steroids, antihistamines, and prednisone.

Plants can contribute to a variety of dermatoses. The Toxicodendron genus, which includes poison ivy, poison oak, and poison sumac, is a well-known and common cause of allergic contact dermatitis (ACD), but many other plants can cause direct or airborne contact dermatitis, especially in gardeners, florists, and farmers. This article provides an overview of different plant-related dermatoses and culprit plants as well as how these dermatoses should be diagnosed and treated.

Epidemiology

Plant dermatoses affect more than 50 million individuals each year.^1,2 In the United States, the Toxicodendron genus causes ACD in more than 70% of exposed individuals, leading to medical visits.³ An urgent care visit for a plant-related dermatitis is estimated to cost $168, while an emergency department visit can cost 3 times as much.⁴ Although less common, Compositae plants are another important culprit of plant dermatitis, particularly in gardeners, florists, and farmers. Data from the 2017-2018 North American Contact Dermatitis Group screening series (N=4947) showed sesquiterpene lactones and Compositae to be positive in 0.5% of patch-tested patients.⁵

Plant Dermatitis Classifications

Plant dermatitis can be classified into 5 main categories: ACD, mechanical irritant contact dermatitis, chemical irritant contact dermatitis, light-mediated dermatitis, and pseudophytodermatitis.⁶

Allergic contact dermatitis is an immune-mediated type IV delayed hypersensitivity reaction. The common molecular allergens in plants include phenols, α-methylene-γ-butyrolactones, quinones, terpenes, disulfides, isothiocyanates, and polyacetylenic derivatives.⁶

Plant contact dermatitis due to mechanical and chemical irritants is precipitated by multiple mechanisms, including disruption of the epidermal barrier and subsequent cytokine release from keratinocytes.⁷ Nonimmunologic contact urticaria from plants is thought to be a type of irritant reaction precipitated by mechanical or chemical trauma.⁸

Light-mediated dermatitis includes phytophotodermatitis and photoallergic contact dermatitis. Phytophotodermatitis is a phototoxic reaction triggered by exposure to both plant-derived furanocoumarin and UVA light.⁹ By contrast, photoallergic contact dermatitis is a delayed hypersensitivity reaction from prior sensitization to a light-activated antigen.¹⁰

Pseudophytodermatitis, as its name implies, is not truly mediated by an allergen or irritant intrinsic to the plant but rather by dyes, waxes, insecticides, or arthropods that inhabit the plant or are secondarily applied.⁶

Common Plant Allergens

Anacardiaceae Family
Most of the allergenic plants within the Anacardiaceae family belong to the Toxicodendron genus, which encompasses poison ivy (Toxicodendron radicans), poison oak (Toxicodendron pubescens,Toxicodendron quercifolium, Toxicodendron diversiloum), and poison sumac (Toxicodendron vernix). Poison ivy is the celebrity of the Anacardiaceae family and contributes to most cases of plant-related ACD. It is found in every state in the continental United States. Poison oak is another common culprit found in the western and southeastern United States.¹¹ Plants within the Anacardiaceae family contain an oleoresin called urushiol, which is the primary sensitizing substance. Although poison ivy and poison oak grow well in full sun to partial shade, poison sumac typically is found in damp swampy areas east of the Rocky Mountains. Most cases of ACD related to Anacardiaceae species are due to direct contact with urushiol from a Toxicodendron plant, but burning of brush containing Toxicodendron can cause airborne exposure when urushiol oil is carried by smoke particles.¹² Sensitization to Toxicodendron can cause ACD to other Anacardiaceae species such as the Japanese lacquer tree (Toxicodendron vernicifluum), mango tree (Mangifera indica), cashew tree (Anacardium occidentale), and Indian marking nut tree (Semecarpus anacardium).⁶ Cross-reactions to components of the ginkgo tree (Ginkgo biloba) also are possible.

Toxicodendron plants can be more easily identified and avoided with knowledge of their characteristic leaf patterns. The most dependable way to identify poison ivy and poison oak species is to look for plants with 3 leaves, giving rise to the common saying, “Leaves of three, leave them be.” Poison sumac plants have groups of 7 to 13 leaves arranged as pairs along a central rib. Another helpful finding is a black deposit that Toxicodendron species leave behind following trauma to the leaves. Urushiol oxidizes when exposed to air and turns into a black deposit that can be seen on damaged leaves themselves or can be demonstrated in a black spot test to verify if a plant is a Toxicodendron species. The test is performed by gathering (carefully, without direct contact) a few leaves in a paper towel and crushing them to release sap. Within minutes, the sap will turn black if the plant is indeed a Toxicodendron species.¹³Pruritic, edematous, erythematous papules, plaques, and eventual vesicles in a linear distribution are suspicious for Toxicodendron exposure. Although your pet will not develop Toxicodendron ACD, oleoresin-contaminated pets can transfer the oils to their owners after coming into contact with these plants. Toxicodendron dermatitis also can be acquired from oleoresin-contaminated fomites such as clothing and shoes worn in the garden or when hiking. Toxicodendron dermatitis can appear at different sites on the body at different times depending on the amount of oleoresin exposure as well as epidermal thickness. For example, the oleoresin can be transferred from the hands to body areas with a thinner stratum corneum (eg, genitalia) and cause subsequent dermatitis.¹

Compositae Family
The Compositae family (also known as Asteraceae) is a large plant family with more than 20,000 species, including numerous weeds, wildflowers, and vegetables. The flowers, leaves, stems, and pollens of the Compositae family are coated by cyclic esters called sesquiterpene lactones. Mitchell and Dupuis¹⁴ showed that sesquiterpene lactones are the allergens responsible for ACD to various Compositae plants, including ragweed (Ambrosia), sneezeweed (Helenium), and chrysanthemums (Chrysanthemum). Common Compositae vegetables such as lettuce (Lactuca sativa) have been reported to cause ACD in chefs, grocery store produce handlers, gardeners, and even owners of lettuce-eating pet guinea pigs and turtles.¹⁵ Similarly, artichokes (Cynara scolymus) can cause ACD in gardeners.¹⁶ Exposure to Compositae species also has been implicated in photoallergic reactions, and studies have demonstrated that some patients with chronic actinic dermatitis also have positive patch test reactions to Compositae species and/or sesquiterpene lactones.^17,18

In addition to direct contact with Compositae plants, airborne exposure to sesquiterpene lactones can cause ACD.¹⁴ The pattern of airborne contact dermatitis typically involves exposed areas such as the eyelids, central face, and/or neck. The beak sign also can be a clue to airborne contact dermatitis, which involves dermatitis of the face that spares the nasal tip and/or nasal ridge. It is thought that the beak sign may result from increased sebaceous gland concentration on the nose, which prevents penetration of allergens and irritants.¹⁹ Unlike photoallergic contact dermatitis, which also can involve the face, airborne ACD frequently involves photoprotected areas such as the submandibular chin and the upper lip. Davies and Kersey²⁰ reported the case of a groundsman who was cutting grass with dandelions (Taraxacum officinale) and was found to have associated airborne ACD of the face, neck, and forearms due to Compositae allergy. In a different setting, the aromas of chamomile (Matricaria chamomilla) have been reported to cause airborne ACD in a tea drinker.²¹ Paulsen²² found that ingestion of chamomile tea can induce systemic ACD in sensitized individuals.

Alstroemeriaceae, Liliaceae, and Primulaceae
Florists are exposed to many plant species and have a high prevalence of ACD. Thiboutot et al²³ found that 15 of 57 (26%) floral workers experienced hand dermatitis that cleared with time away from work. The Peruvian lily (Alstroemeria, Alstroemeriaceae family), which contains tuliposide A, was found to be the leading cause of sensitization.²³ Tulips (Tulipa, Liliaceae family), as the flower name suggests, also contain tuliposide A, which along with mechanical irritation from the course tecta fibers on the bulbs lead to a dermatitis known as tulip fingers.^24,25 Poison primrose (Primula obconica, Primulaceae family), cultivated for its highly colorful flowers, contains the contact allergen primin.⁶ A common clinical presentation of ACD for any of these culprit flowers is localized dermatitis of the thumb and index finger in a florist or gardener.

Plants That Cause Irritant Reactions

Cactuses
Although the long spines of the Cactaceae family of cactuses is a warning for passersby, it is the small and nearly invisible barbed hairs (glochids) that inflict a more dramatic cutaneous reaction. The prickly pear cactus (Opuntia species) is a good example of such a plant, as its glochids cause mechanical irritation but also can become embedded in the skin and result in subcutaneous granulomas known as sabra dermatitis.²⁶

Stinging Nettle
The dermatologic term urticaria owes its namesake to the stinging nettle plant, which comes from the family Urticaceae. The stinging nettle has small hairs on its leaves, referred to as stinging trichomes, which have needlelike tips that pierce the skin and inject a mix of histamine, formic acid, and acetylcholine, causing a pruritic dermatitis that may last up to 12 hours.²⁷ The plant is found worldwide and is a common weed in North America.

Phytophotodermatitis

Lemons and limes (Rutaceae family) are common culprits of phytophotodermatitis, often causing what is known as a margarita burn after outdoor consumption or preparation of this tasty citrus beverage.²⁸ An accidental spray of lime juice on the skin while adding it to a beer, guacamole, salsa, or any other food or beverage also can cause phytophotodermatitis.^29-31 Although the juice of lemons and limes contains psoralens, the rind can contain a 6- to 186-fold increased concentration.³² Psoralen is the photoactive agent in Rutaceae plants that intercalates in double-stranded DNA and promotes intrastrand cross-links when exposed to UVA light, which ultimately leads to dermatitis.⁹ Phytophotodermatitis commonly causes erythema, edema, and painful bullae on sun-exposed areas and classically heals with hyperpigmentation.

Pseudophytodermatitis can occur in grain farmers and harvesters who handle wheat and/or barley and incidentally come in contact with insects and chemicals on the plant material. Pseudophytodermatitis from mites in the wheat and/or barley plant can occur at harvest time when contact with the plant material is high. Insects such as the North American itch mite (Pediculoides ventricosus) can cause petechiae, wheals, and pustules. In addition, insecticides such as malathion and arsenical sprays that are applied to plant leaves can cause pseudophytodermatitis, which may be initially diagnosed as dermatitis to the plant itself.⁶

Patch Testing to Plants

When a patient presents with recurrent or persistent dermatitis and a plant contact allergen is suspected, patch testing is indicated. Most comprehensive patch test series contain various plant allergens, such as sesquiterpene lactones, Compositae mix, and limonene hydroperoxides, and patch testing to a specialized plant series may be necessary. Poison ivy/oak/sumac allergens typically are not included in patch test series because of the high prevalence of allergic reactions to these chemicals and the likelihood of sensitization when patch testing with urushiol. Compositae contact sensitization can be difficult to diagnose because neither sesquiterpene lactone mix 0.1% nor parthenolide 0.1% are sensitive enough to pick up all Compositae allergies.^33,34 Paulsen and Andersen³⁴ proposed that if Compositae sensitization is suspected, testing should include sesquiterpene lactone, parthenolide, and Compositae mix II 2.5%, as well as other potential Compositae allergens based on the patient’s history.³⁴

Because plants can have geographic variability and contain potentially unknown allergens,³⁵ testing to plant components may increase the diagnostic yield of patch testing. Dividing the plant into component parts (ie, stem, bulb, leaf, flower) is helpful, as different components have different allergen concentrations. It is important to consult expert resources before proceeding with plant component patch testing because irritant reactions are frequent and may confound the testing.³⁶

Prevention and Treatment

For all plant dermatoses, the mainstay of prevention is to avoid contact with the offending plant material. Gloves can be an important protective tool for plant dermatitis prevention; the correct material depends on the plant species being handled. Rubber gloves should not be worn to protect against Toxicodendron plants since the catechols in urushiol are soluble in rubber; vinyl gloves should be worn instead.⁶ Marks³⁷ found that tuliposide A, the allergen in the Peruvian lily (Alstroemeria), penetrates both vinyl and latex gloves; it does not penetrate nitrile gloves. If exposed, the risk of dermatitis can be decreased if the allergen is washed away with soap and water as soon as possible. Some allergens such as Toxicodendron are absorbed quickly and need to be washed off within 10 minutes of exposure.⁶ Importantly, exposed gardening gloves may continue to perpetuate ACD if the allergen is not also washed off the gloves themselves.

For light-mediated dermatoses, sun avoidance or use of an effective sunscreen can reduce symptoms in an individual who has already been exposed.¹⁰ UVA light activates psoralen-mediated dermatitis but not until 30 to 120 minutes after absorption into the skin.³⁸

Barrier creams are thought to be protective against plant ACD through a variety of mechanisms. The cream itself is meant to reduce skin contact to an allergen or irritant. Additionally, barrier creams contain active ingredients such as silicone, hydrocarbons, and aluminum chlorohydrate, which are thought to trap or transform offending agents before contacting the skin. When contact with a Toxicodendron species is anticipated, Marks et al³⁹ found that dermatitis was absent or significantly reduced when 144 patients were pretreated with quaternium-18 bentonite lotion 5% (P<.0001).

Although allergen avoidance and use of gloves and barrier creams are the mainstays of preventing plant dermatoses, treatment often is required to control postexposure symptoms. For all plant dermatoses, topical corticosteroids can be used to reduce inflammation and pruritus. In some cases, systemic steroids may be necessary. To prevent rebound of dermatitis, patients often require a 3-week or longer course of oral steroids to quell the reaction, particularly if the dermatitis is vigorous or an id reaction is present.⁴⁰ Antihistamines and cold compresses also can provide symptomatic relief.

Final Interpretation

Plants can cause a variety of dermatoses. Although Toxicodendron plants are the most frequent cause of ACD, it is important to keep in mind that florists, gardeners, and farmers are exposed to a large variety of allergens, irritants, and phototoxic agents that cause dermatoses as well. Confirmation of plant-induced ACD involves patch testing against suspected species. Prevention involves use of appropriate barriers and avoidance of implicated plants. Treatment includes topical steroids, antihistamines, and prednisone.

Plants can contribute to a variety of dermatoses. The Toxicodendron genus, which includes poison ivy, poison oak, and poison sumac, is a well-known and common cause of allergic contact dermatitis (ACD), but many other plants can cause direct or airborne contact dermatitis, especially in gardeners, florists, and farmers. This article provides an overview of different plant-related dermatoses and culprit plants as well as how these dermatoses should be diagnosed and treated.

Epidemiology

Plant dermatoses affect more than 50 million individuals each year.^1,2 In the United States, the Toxicodendron genus causes ACD in more than 70% of exposed individuals, leading to medical visits.³ An urgent care visit for a plant-related dermatitis is estimated to cost $168, while an emergency department visit can cost 3 times as much.⁴ Although less common, Compositae plants are another important culprit of plant dermatitis, particularly in gardeners, florists, and farmers. Data from the 2017-2018 North American Contact Dermatitis Group screening series (N=4947) showed sesquiterpene lactones and Compositae to be positive in 0.5% of patch-tested patients.⁵

Plant Dermatitis Classifications

Plant dermatitis can be classified into 5 main categories: ACD, mechanical irritant contact dermatitis, chemical irritant contact dermatitis, light-mediated dermatitis, and pseudophytodermatitis.⁶

Allergic contact dermatitis is an immune-mediated type IV delayed hypersensitivity reaction. The common molecular allergens in plants include phenols, α-methylene-γ-butyrolactones, quinones, terpenes, disulfides, isothiocyanates, and polyacetylenic derivatives.⁶

Plant contact dermatitis due to mechanical and chemical irritants is precipitated by multiple mechanisms, including disruption of the epidermal barrier and subsequent cytokine release from keratinocytes.⁷ Nonimmunologic contact urticaria from plants is thought to be a type of irritant reaction precipitated by mechanical or chemical trauma.⁸

Light-mediated dermatitis includes phytophotodermatitis and photoallergic contact dermatitis. Phytophotodermatitis is a phototoxic reaction triggered by exposure to both plant-derived furanocoumarin and UVA light.⁹ By contrast, photoallergic contact dermatitis is a delayed hypersensitivity reaction from prior sensitization to a light-activated antigen.¹⁰

Pseudophytodermatitis, as its name implies, is not truly mediated by an allergen or irritant intrinsic to the plant but rather by dyes, waxes, insecticides, or arthropods that inhabit the plant or are secondarily applied.⁶

Common Plant Allergens

Anacardiaceae Family
Most of the allergenic plants within the Anacardiaceae family belong to the Toxicodendron genus, which encompasses poison ivy (Toxicodendron radicans), poison oak (Toxicodendron pubescens,Toxicodendron quercifolium, Toxicodendron diversiloum), and poison sumac (Toxicodendron vernix). Poison ivy is the celebrity of the Anacardiaceae family and contributes to most cases of plant-related ACD. It is found in every state in the continental United States. Poison oak is another common culprit found in the western and southeastern United States.¹¹ Plants within the Anacardiaceae family contain an oleoresin called urushiol, which is the primary sensitizing substance. Although poison ivy and poison oak grow well in full sun to partial shade, poison sumac typically is found in damp swampy areas east of the Rocky Mountains. Most cases of ACD related to Anacardiaceae species are due to direct contact with urushiol from a Toxicodendron plant, but burning of brush containing Toxicodendron can cause airborne exposure when urushiol oil is carried by smoke particles.¹² Sensitization to Toxicodendron can cause ACD to other Anacardiaceae species such as the Japanese lacquer tree (Toxicodendron vernicifluum), mango tree (Mangifera indica), cashew tree (Anacardium occidentale), and Indian marking nut tree (Semecarpus anacardium).⁶ Cross-reactions to components of the ginkgo tree (Ginkgo biloba) also are possible.

Toxicodendron plants can be more easily identified and avoided with knowledge of their characteristic leaf patterns. The most dependable way to identify poison ivy and poison oak species is to look for plants with 3 leaves, giving rise to the common saying, “Leaves of three, leave them be.” Poison sumac plants have groups of 7 to 13 leaves arranged as pairs along a central rib. Another helpful finding is a black deposit that Toxicodendron species leave behind following trauma to the leaves. Urushiol oxidizes when exposed to air and turns into a black deposit that can be seen on damaged leaves themselves or can be demonstrated in a black spot test to verify if a plant is a Toxicodendron species. The test is performed by gathering (carefully, without direct contact) a few leaves in a paper towel and crushing them to release sap. Within minutes, the sap will turn black if the plant is indeed a Toxicodendron species.¹³Pruritic, edematous, erythematous papules, plaques, and eventual vesicles in a linear distribution are suspicious for Toxicodendron exposure. Although your pet will not develop Toxicodendron ACD, oleoresin-contaminated pets can transfer the oils to their owners after coming into contact with these plants. Toxicodendron dermatitis also can be acquired from oleoresin-contaminated fomites such as clothing and shoes worn in the garden or when hiking. Toxicodendron dermatitis can appear at different sites on the body at different times depending on the amount of oleoresin exposure as well as epidermal thickness. For example, the oleoresin can be transferred from the hands to body areas with a thinner stratum corneum (eg, genitalia) and cause subsequent dermatitis.¹

Compositae Family
The Compositae family (also known as Asteraceae) is a large plant family with more than 20,000 species, including numerous weeds, wildflowers, and vegetables. The flowers, leaves, stems, and pollens of the Compositae family are coated by cyclic esters called sesquiterpene lactones. Mitchell and Dupuis¹⁴ showed that sesquiterpene lactones are the allergens responsible for ACD to various Compositae plants, including ragweed (Ambrosia), sneezeweed (Helenium), and chrysanthemums (Chrysanthemum). Common Compositae vegetables such as lettuce (Lactuca sativa) have been reported to cause ACD in chefs, grocery store produce handlers, gardeners, and even owners of lettuce-eating pet guinea pigs and turtles.¹⁵ Similarly, artichokes (Cynara scolymus) can cause ACD in gardeners.¹⁶ Exposure to Compositae species also has been implicated in photoallergic reactions, and studies have demonstrated that some patients with chronic actinic dermatitis also have positive patch test reactions to Compositae species and/or sesquiterpene lactones.^17,18

In addition to direct contact with Compositae plants, airborne exposure to sesquiterpene lactones can cause ACD.¹⁴ The pattern of airborne contact dermatitis typically involves exposed areas such as the eyelids, central face, and/or neck. The beak sign also can be a clue to airborne contact dermatitis, which involves dermatitis of the face that spares the nasal tip and/or nasal ridge. It is thought that the beak sign may result from increased sebaceous gland concentration on the nose, which prevents penetration of allergens and irritants.¹⁹ Unlike photoallergic contact dermatitis, which also can involve the face, airborne ACD frequently involves photoprotected areas such as the submandibular chin and the upper lip. Davies and Kersey²⁰ reported the case of a groundsman who was cutting grass with dandelions (Taraxacum officinale) and was found to have associated airborne ACD of the face, neck, and forearms due to Compositae allergy. In a different setting, the aromas of chamomile (Matricaria chamomilla) have been reported to cause airborne ACD in a tea drinker.²¹ Paulsen²² found that ingestion of chamomile tea can induce systemic ACD in sensitized individuals.

Alstroemeriaceae, Liliaceae, and Primulaceae
Florists are exposed to many plant species and have a high prevalence of ACD. Thiboutot et al²³ found that 15 of 57 (26%) floral workers experienced hand dermatitis that cleared with time away from work. The Peruvian lily (Alstroemeria, Alstroemeriaceae family), which contains tuliposide A, was found to be the leading cause of sensitization.²³ Tulips (Tulipa, Liliaceae family), as the flower name suggests, also contain tuliposide A, which along with mechanical irritation from the course tecta fibers on the bulbs lead to a dermatitis known as tulip fingers.^24,25 Poison primrose (Primula obconica, Primulaceae family), cultivated for its highly colorful flowers, contains the contact allergen primin.⁶ A common clinical presentation of ACD for any of these culprit flowers is localized dermatitis of the thumb and index finger in a florist or gardener.

Plants That Cause Irritant Reactions

Cactuses
Although the long spines of the Cactaceae family of cactuses is a warning for passersby, it is the small and nearly invisible barbed hairs (glochids) that inflict a more dramatic cutaneous reaction. The prickly pear cactus (Opuntia species) is a good example of such a plant, as its glochids cause mechanical irritation but also can become embedded in the skin and result in subcutaneous granulomas known as sabra dermatitis.²⁶

Stinging Nettle
The dermatologic term urticaria owes its namesake to the stinging nettle plant, which comes from the family Urticaceae. The stinging nettle has small hairs on its leaves, referred to as stinging trichomes, which have needlelike tips that pierce the skin and inject a mix of histamine, formic acid, and acetylcholine, causing a pruritic dermatitis that may last up to 12 hours.²⁷ The plant is found worldwide and is a common weed in North America.

Phytophotodermatitis

Lemons and limes (Rutaceae family) are common culprits of phytophotodermatitis, often causing what is known as a margarita burn after outdoor consumption or preparation of this tasty citrus beverage.²⁸ An accidental spray of lime juice on the skin while adding it to a beer, guacamole, salsa, or any other food or beverage also can cause phytophotodermatitis.^29-31 Although the juice of lemons and limes contains psoralens, the rind can contain a 6- to 186-fold increased concentration.³² Psoralen is the photoactive agent in Rutaceae plants that intercalates in double-stranded DNA and promotes intrastrand cross-links when exposed to UVA light, which ultimately leads to dermatitis.⁹ Phytophotodermatitis commonly causes erythema, edema, and painful bullae on sun-exposed areas and classically heals with hyperpigmentation.

Pseudophytodermatitis can occur in grain farmers and harvesters who handle wheat and/or barley and incidentally come in contact with insects and chemicals on the plant material. Pseudophytodermatitis from mites in the wheat and/or barley plant can occur at harvest time when contact with the plant material is high. Insects such as the North American itch mite (Pediculoides ventricosus) can cause petechiae, wheals, and pustules. In addition, insecticides such as malathion and arsenical sprays that are applied to plant leaves can cause pseudophytodermatitis, which may be initially diagnosed as dermatitis to the plant itself.⁶

Patch Testing to Plants

When a patient presents with recurrent or persistent dermatitis and a plant contact allergen is suspected, patch testing is indicated. Most comprehensive patch test series contain various plant allergens, such as sesquiterpene lactones, Compositae mix, and limonene hydroperoxides, and patch testing to a specialized plant series may be necessary. Poison ivy/oak/sumac allergens typically are not included in patch test series because of the high prevalence of allergic reactions to these chemicals and the likelihood of sensitization when patch testing with urushiol. Compositae contact sensitization can be difficult to diagnose because neither sesquiterpene lactone mix 0.1% nor parthenolide 0.1% are sensitive enough to pick up all Compositae allergies.^33,34 Paulsen and Andersen³⁴ proposed that if Compositae sensitization is suspected, testing should include sesquiterpene lactone, parthenolide, and Compositae mix II 2.5%, as well as other potential Compositae allergens based on the patient’s history.³⁴

Because plants can have geographic variability and contain potentially unknown allergens,³⁵ testing to plant components may increase the diagnostic yield of patch testing. Dividing the plant into component parts (ie, stem, bulb, leaf, flower) is helpful, as different components have different allergen concentrations. It is important to consult expert resources before proceeding with plant component patch testing because irritant reactions are frequent and may confound the testing.³⁶

Prevention and Treatment

For all plant dermatoses, the mainstay of prevention is to avoid contact with the offending plant material. Gloves can be an important protective tool for plant dermatitis prevention; the correct material depends on the plant species being handled. Rubber gloves should not be worn to protect against Toxicodendron plants since the catechols in urushiol are soluble in rubber; vinyl gloves should be worn instead.⁶ Marks³⁷ found that tuliposide A, the allergen in the Peruvian lily (Alstroemeria), penetrates both vinyl and latex gloves; it does not penetrate nitrile gloves. If exposed, the risk of dermatitis can be decreased if the allergen is washed away with soap and water as soon as possible. Some allergens such as Toxicodendron are absorbed quickly and need to be washed off within 10 minutes of exposure.⁶ Importantly, exposed gardening gloves may continue to perpetuate ACD if the allergen is not also washed off the gloves themselves.

For light-mediated dermatoses, sun avoidance or use of an effective sunscreen can reduce symptoms in an individual who has already been exposed.¹⁰ UVA light activates psoralen-mediated dermatitis but not until 30 to 120 minutes after absorption into the skin.³⁸

Barrier creams are thought to be protective against plant ACD through a variety of mechanisms. The cream itself is meant to reduce skin contact to an allergen or irritant. Additionally, barrier creams contain active ingredients such as silicone, hydrocarbons, and aluminum chlorohydrate, which are thought to trap or transform offending agents before contacting the skin. When contact with a Toxicodendron species is anticipated, Marks et al³⁹ found that dermatitis was absent or significantly reduced when 144 patients were pretreated with quaternium-18 bentonite lotion 5% (P<.0001).

Although allergen avoidance and use of gloves and barrier creams are the mainstays of preventing plant dermatoses, treatment often is required to control postexposure symptoms. For all plant dermatoses, topical corticosteroids can be used to reduce inflammation and pruritus. In some cases, systemic steroids may be necessary. To prevent rebound of dermatitis, patients often require a 3-week or longer course of oral steroids to quell the reaction, particularly if the dermatitis is vigorous or an id reaction is present.⁴⁰ Antihistamines and cold compresses also can provide symptomatic relief.

Final Interpretation

Plants can cause a variety of dermatoses. Although Toxicodendron plants are the most frequent cause of ACD, it is important to keep in mind that florists, gardeners, and farmers are exposed to a large variety of allergens, irritants, and phototoxic agents that cause dermatoses as well. Confirmation of plant-induced ACD involves patch testing against suspected species. Prevention involves use of appropriate barriers and avoidance of implicated plants. Treatment includes topical steroids, antihistamines, and prednisone.

A large, real-world test of face masks in Bangladesh shows that masks work to reduce community spread of COVID-19. It also shows that surgical masks are more effective than cloth face coverings.

OsakaWayne Studios/Moment

The study, which was published ahead of peer review, demonstrates the power of careful investigation and offers a host of lessons about mask wearing that will be important worldwide. One key finding of the study, for example, is that wearing a mask doesn’t lead people to abandon social distancing, something public health officials had feared might happen if masks gave people a false sense of security.

“What we really were able to achieve is to demonstrate that masks are effective against COVID-19, even under a rigorous and systematic evaluation that was done in the throes of the pandemic,” said Ashley Styczynski, MD, who was an infectious disease fellow at Stanford (Calif.) University when she collaborated on the study with other colleagues at Stanford, Yale, and Innovations for Poverty Action, a large research and policy nonprofit organization that currently works in 22 countries.

“And so, I think people who have been holding out on wearing masks because [they] felt like there wasn’t enough evidence for it, we’re hoping this will really help bridge that gap for them,” she said.

It included more than 600 unions – or local governmental districts in Bangladesh – and roughly 340,000 people.

Half of the districts were given cloth or surgical face masks along with continual reminders to wear them properly; the other half were tracked with no intervention. Blood tests of people who developed symptoms during the study verified their infections.

Compared to villages that didn’t mask, those in which masks of any type were worn had about 9% fewer symptomatic cases of COVID-19. The finding was statistically significant and was unlikely to have occurred by chance alone.

“Somebody could read this study and say, ‘OK, you reduced COVID-19 by 9%. Big deal.’ And what I would respond to that would be that, if anything, we think that that is a substantial underestimate,” Dr. Styczynski said.

One reason they think they underestimated the effectiveness of masks is that they tested only people who were having symptoms, so people who had only very mild or asymptomatic infections were missed.

Another reason is that, among people who had symptoms, only one-third agreed to undergo a blood test. The effect may have been bigger had participation been universal.

Local transmission may have played a role, too. Rates of COVID-19 in Bangladesh were relatively low during the study. Most infections were caused by the B.1.1.7, or Alpha, variant.

Since then, Delta has taken over. Delta is thought to be more transmissible, and some studies have suggested that people infected with Delta shed more viral particles. Masks may be more effective when more virus is circulating.

The investigators also found important differences by age and by the type of mask. Villages in which surgical masks were worn had 11% fewer COVID-19 cases than villages in which masks were not worn. In villages in which cloth masks were worn, on the other hand, infections were reduced by only 5%.

The cloth masks were substantial. Each had three layers – two layers of fabric with an outer layer of polypropylene. On testing, the filtration efficiency of the cloth masks was only about 37%, compared with 95% for the three-layer surgical masks, which were also made of polypropylene.

Masks were most effective for older individuals. People aged 50-60 years who wore surgical masks were 23% less likely to test positive for COVID, compared with their peers who didn’t wear masks. For people older than 60, the reduction in risk was greater – 35%.
 

Rigorous research

The study took place over a period of 8 weeks in each district. The interventions were rolled out in waves, with the first starting in November 2020 and the last in January 2021.

Investigators gave each household free cloth or surgical face masks and showed families a video about proper mask wearing with promotional messages from the prime minister, a head imam, and a national cricket star. They also handed out free masks.

Previous studies have shown that people aren’t always truthful about wearing masks in public. In Kenya, for example, 88% of people answering a phone survey said that they wore masks regularly, but researchers determined that only 10% of them actually did so.

Investigators in the Bangladesh study didn’t just ask people if they’d worn masks, they stationed themselves in public markets, mosques, tea stalls, and on roads that were the main entrances to the villages and took notes.

They also tested various ways to educate people and to remind them to wear masks. They found that four factors were effective at promoting the wearing of masks, and they gave them an acronym – NORM.

• N for no-cost masks.
• O for offering information through the video and local leaders.
• R for regular reminders to people by investigators who stand in public markets and offer masks or encourage anyone who wasn’t wearing one or wasn’t wearing it correctly.
• M for modeling, in which local leaders, such as imams, wear masks and remind their followers to wear them.

These four measures tripled the wearing of masks in the intervention communities, from a baseline level of 13% to 42%. People continued to wear their masks properly for about 2 weeks after the study ended, indicating that they’d gotten used to wearing them.

Dr. Styczynski said that nothing else – not text message reminders, or signs posted in public places, or local incentives – moved the needle on mask wearing.
 

Saved lives and money

The study found that the strategy was cost effective, too. Giving masks to a large population and getting people to use them costs about $10,000 per life saved from COVID, on par with the cost of deploying mosquito nets to save people from malaria, Dr. Styczynski said.

“I think that what we’ve been able to show is that this is a really important tool to be used globally, especially as countries have delays in getting access to vaccines and rolling them out,” she said.

Dr. Styczynski said masks will continue to be important even in countries such as the United States, where vaccines aren’t stopping transmission 100% and there are still large portions of the population who are unvaccinated, such as children.

“If we want to reduce COVID-19 here, it’s really important that we consider the ongoing utility of masks, in addition to vaccines, and not really thinking of them as one or the other,” she said.

The study was funded by a grant from GiveWell.org. The funder had no role in the study design, interpretation, or the decision to publish.

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

A large, real-world test of face masks in Bangladesh shows that masks work to reduce community spread of COVID-19. It also shows that surgical masks are more effective than cloth face coverings.

OsakaWayne Studios/Moment

The study, which was published ahead of peer review, demonstrates the power of careful investigation and offers a host of lessons about mask wearing that will be important worldwide. One key finding of the study, for example, is that wearing a mask doesn’t lead people to abandon social distancing, something public health officials had feared might happen if masks gave people a false sense of security.

“What we really were able to achieve is to demonstrate that masks are effective against COVID-19, even under a rigorous and systematic evaluation that was done in the throes of the pandemic,” said Ashley Styczynski, MD, who was an infectious disease fellow at Stanford (Calif.) University when she collaborated on the study with other colleagues at Stanford, Yale, and Innovations for Poverty Action, a large research and policy nonprofit organization that currently works in 22 countries.

“And so, I think people who have been holding out on wearing masks because [they] felt like there wasn’t enough evidence for it, we’re hoping this will really help bridge that gap for them,” she said.

It included more than 600 unions – or local governmental districts in Bangladesh – and roughly 340,000 people.

Half of the districts were given cloth or surgical face masks along with continual reminders to wear them properly; the other half were tracked with no intervention. Blood tests of people who developed symptoms during the study verified their infections.

Compared to villages that didn’t mask, those in which masks of any type were worn had about 9% fewer symptomatic cases of COVID-19. The finding was statistically significant and was unlikely to have occurred by chance alone.

“Somebody could read this study and say, ‘OK, you reduced COVID-19 by 9%. Big deal.’ And what I would respond to that would be that, if anything, we think that that is a substantial underestimate,” Dr. Styczynski said.

One reason they think they underestimated the effectiveness of masks is that they tested only people who were having symptoms, so people who had only very mild or asymptomatic infections were missed.

Another reason is that, among people who had symptoms, only one-third agreed to undergo a blood test. The effect may have been bigger had participation been universal.

Local transmission may have played a role, too. Rates of COVID-19 in Bangladesh were relatively low during the study. Most infections were caused by the B.1.1.7, or Alpha, variant.

Since then, Delta has taken over. Delta is thought to be more transmissible, and some studies have suggested that people infected with Delta shed more viral particles. Masks may be more effective when more virus is circulating.

The investigators also found important differences by age and by the type of mask. Villages in which surgical masks were worn had 11% fewer COVID-19 cases than villages in which masks were not worn. In villages in which cloth masks were worn, on the other hand, infections were reduced by only 5%.

The cloth masks were substantial. Each had three layers – two layers of fabric with an outer layer of polypropylene. On testing, the filtration efficiency of the cloth masks was only about 37%, compared with 95% for the three-layer surgical masks, which were also made of polypropylene.

Masks were most effective for older individuals. People aged 50-60 years who wore surgical masks were 23% less likely to test positive for COVID, compared with their peers who didn’t wear masks. For people older than 60, the reduction in risk was greater – 35%.
 

Rigorous research

The study took place over a period of 8 weeks in each district. The interventions were rolled out in waves, with the first starting in November 2020 and the last in January 2021.

Investigators gave each household free cloth or surgical face masks and showed families a video about proper mask wearing with promotional messages from the prime minister, a head imam, and a national cricket star. They also handed out free masks.

Previous studies have shown that people aren’t always truthful about wearing masks in public. In Kenya, for example, 88% of people answering a phone survey said that they wore masks regularly, but researchers determined that only 10% of them actually did so.

Investigators in the Bangladesh study didn’t just ask people if they’d worn masks, they stationed themselves in public markets, mosques, tea stalls, and on roads that were the main entrances to the villages and took notes.

They also tested various ways to educate people and to remind them to wear masks. They found that four factors were effective at promoting the wearing of masks, and they gave them an acronym – NORM.

• N for no-cost masks.
• O for offering information through the video and local leaders.
• R for regular reminders to people by investigators who stand in public markets and offer masks or encourage anyone who wasn’t wearing one or wasn’t wearing it correctly.
• M for modeling, in which local leaders, such as imams, wear masks and remind their followers to wear them.

These four measures tripled the wearing of masks in the intervention communities, from a baseline level of 13% to 42%. People continued to wear their masks properly for about 2 weeks after the study ended, indicating that they’d gotten used to wearing them.

Dr. Styczynski said that nothing else – not text message reminders, or signs posted in public places, or local incentives – moved the needle on mask wearing.
 

Saved lives and money

The study found that the strategy was cost effective, too. Giving masks to a large population and getting people to use them costs about $10,000 per life saved from COVID, on par with the cost of deploying mosquito nets to save people from malaria, Dr. Styczynski said.

“I think that what we’ve been able to show is that this is a really important tool to be used globally, especially as countries have delays in getting access to vaccines and rolling them out,” she said.

Dr. Styczynski said masks will continue to be important even in countries such as the United States, where vaccines aren’t stopping transmission 100% and there are still large portions of the population who are unvaccinated, such as children.

“If we want to reduce COVID-19 here, it’s really important that we consider the ongoing utility of masks, in addition to vaccines, and not really thinking of them as one or the other,” she said.

The study was funded by a grant from GiveWell.org. The funder had no role in the study design, interpretation, or the decision to publish.

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

A large, real-world test of face masks in Bangladesh shows that masks work to reduce community spread of COVID-19. It also shows that surgical masks are more effective than cloth face coverings.

OsakaWayne Studios/Moment

The study, which was published ahead of peer review, demonstrates the power of careful investigation and offers a host of lessons about mask wearing that will be important worldwide. One key finding of the study, for example, is that wearing a mask doesn’t lead people to abandon social distancing, something public health officials had feared might happen if masks gave people a false sense of security.

“What we really were able to achieve is to demonstrate that masks are effective against COVID-19, even under a rigorous and systematic evaluation that was done in the throes of the pandemic,” said Ashley Styczynski, MD, who was an infectious disease fellow at Stanford (Calif.) University when she collaborated on the study with other colleagues at Stanford, Yale, and Innovations for Poverty Action, a large research and policy nonprofit organization that currently works in 22 countries.

“And so, I think people who have been holding out on wearing masks because [they] felt like there wasn’t enough evidence for it, we’re hoping this will really help bridge that gap for them,” she said.

It included more than 600 unions – or local governmental districts in Bangladesh – and roughly 340,000 people.

Half of the districts were given cloth or surgical face masks along with continual reminders to wear them properly; the other half were tracked with no intervention. Blood tests of people who developed symptoms during the study verified their infections.

Compared to villages that didn’t mask, those in which masks of any type were worn had about 9% fewer symptomatic cases of COVID-19. The finding was statistically significant and was unlikely to have occurred by chance alone.

“Somebody could read this study and say, ‘OK, you reduced COVID-19 by 9%. Big deal.’ And what I would respond to that would be that, if anything, we think that that is a substantial underestimate,” Dr. Styczynski said.

One reason they think they underestimated the effectiveness of masks is that they tested only people who were having symptoms, so people who had only very mild or asymptomatic infections were missed.

Another reason is that, among people who had symptoms, only one-third agreed to undergo a blood test. The effect may have been bigger had participation been universal.

Local transmission may have played a role, too. Rates of COVID-19 in Bangladesh were relatively low during the study. Most infections were caused by the B.1.1.7, or Alpha, variant.

Since then, Delta has taken over. Delta is thought to be more transmissible, and some studies have suggested that people infected with Delta shed more viral particles. Masks may be more effective when more virus is circulating.

The investigators also found important differences by age and by the type of mask. Villages in which surgical masks were worn had 11% fewer COVID-19 cases than villages in which masks were not worn. In villages in which cloth masks were worn, on the other hand, infections were reduced by only 5%.

The cloth masks were substantial. Each had three layers – two layers of fabric with an outer layer of polypropylene. On testing, the filtration efficiency of the cloth masks was only about 37%, compared with 95% for the three-layer surgical masks, which were also made of polypropylene.

Masks were most effective for older individuals. People aged 50-60 years who wore surgical masks were 23% less likely to test positive for COVID, compared with their peers who didn’t wear masks. For people older than 60, the reduction in risk was greater – 35%.
 

Rigorous research

The study took place over a period of 8 weeks in each district. The interventions were rolled out in waves, with the first starting in November 2020 and the last in January 2021.

Investigators gave each household free cloth or surgical face masks and showed families a video about proper mask wearing with promotional messages from the prime minister, a head imam, and a national cricket star. They also handed out free masks.

Previous studies have shown that people aren’t always truthful about wearing masks in public. In Kenya, for example, 88% of people answering a phone survey said that they wore masks regularly, but researchers determined that only 10% of them actually did so.

Investigators in the Bangladesh study didn’t just ask people if they’d worn masks, they stationed themselves in public markets, mosques, tea stalls, and on roads that were the main entrances to the villages and took notes.

They also tested various ways to educate people and to remind them to wear masks. They found that four factors were effective at promoting the wearing of masks, and they gave them an acronym – NORM.

• N for no-cost masks.
• O for offering information through the video and local leaders.
• R for regular reminders to people by investigators who stand in public markets and offer masks or encourage anyone who wasn’t wearing one or wasn’t wearing it correctly.
• M for modeling, in which local leaders, such as imams, wear masks and remind their followers to wear them.

These four measures tripled the wearing of masks in the intervention communities, from a baseline level of 13% to 42%. People continued to wear their masks properly for about 2 weeks after the study ended, indicating that they’d gotten used to wearing them.

Dr. Styczynski said that nothing else – not text message reminders, or signs posted in public places, or local incentives – moved the needle on mask wearing.
 

Saved lives and money

The study found that the strategy was cost effective, too. Giving masks to a large population and getting people to use them costs about $10,000 per life saved from COVID, on par with the cost of deploying mosquito nets to save people from malaria, Dr. Styczynski said.

“I think that what we’ve been able to show is that this is a really important tool to be used globally, especially as countries have delays in getting access to vaccines and rolling them out,” she said.

Dr. Styczynski said masks will continue to be important even in countries such as the United States, where vaccines aren’t stopping transmission 100% and there are still large portions of the population who are unvaccinated, such as children.

“If we want to reduce COVID-19 here, it’s really important that we consider the ongoing utility of masks, in addition to vaccines, and not really thinking of them as one or the other,” she said.

The study was funded by a grant from GiveWell.org. The funder had no role in the study design, interpretation, or the decision to publish.

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

Atopic dermatitis (AD) is an incredibly common chronic skin disease, affecting up to 25% of children and 7% of adults in the United States.^1,2 Despite the prevalence of this disease and its impact on patient quality of life, research and scholarly work in AD has been limited until recent years. A PubMed search of articles indexed for MEDLINE using the term atopic dermatitis showed that there were fewer than 500 articles published in 2000 and 965 in 2010; with our more recent acceleration in research, there were 2168 articles published in 2020 and more than 1300 published in just the first half of 2021 (through June). This new research includes insights into the pathogenesis of AD and study of the disease impact and comorbidities as well as an extensive amount of drug development and clinical trial work for new topical and systemic therapies.

New Agents to Treat AD

The 2016 approval of crisaborole,³ a phosphodiesterase 4 inhibitor, followed by the approval of dupilumab, an IL-4 and IL-13 pathway inhibitor and the first biologic agent approved for AD,⁴ ushered in a new age of therapy. We currently are awaiting the incorporation of a new set of topical nonsteroidal agents, oral Janus kinase (JAK) inhibitors, and new biologic agents for AD, several of which have completed phase 3 trials and extended safety evaluations. How these new drugs will impact our standard treatment across the spectrum of care for AD is not yet known.

The emergence of new systemic therapies is timely, as the most used systemic medications previously were oral corticosteroids, despite their use being advised against in standard practice guidelines. Other agents such as methotrexate, cyclosporine, azathioprine, and mycophenolate are discussed in the literature and AD treatment guidelines as being potentially useful, though absence of US Food and Drug Administration (FDA) approval and the need for frequent laboratory monitoring, as well as drug-specific side effects and an increased risk of infection, limit their use in the United States, especially in pediatric and adolescent populations.⁵

The approval of dupilumab as a systemic therapy—initially for adults and subsequently for teenagers (12–17 years of age) and then children (6–11 years of age)—has markedly influenced the standard of care for moderate to severe AD. This agent has been shown to have a considerable impact on disease severity and quality of life, with a good safety profile and the added benefit of not requiring continuous (or any) laboratory monitoring.^6-8 Ongoing studies of dupilumab in children (ClinicalTrials.gov identifiers NCT02612454, NCT03346434), including those younger than 1 year,⁹ raise the question of how commonly this medication might be incorporated into care across the entire age spectrum of patients with AD. What standards will there be for assessment of severity, disease impact, and persistence to warrant use in younger ages? Will early treatment with novel systemic agents change the overall course of the disease and minimize the development of comorbidities? The answers to these questions remain to be seen.

JAK Inhibitors for AD
Additional novel therapeutics currently are undergoing studies for treatment of AD, most notably the oral JAK inhibitors upadacitinib,¹⁰ baricitinib,¹¹ and abrocitinib.¹² Each of these agents has completed phase 3 trials for AD. Two of these agents—upadacitinib and baricitinib—have prior FDA approval for use in other disease states. Of note, baricitinib is already approved for treatment of moderate to severe AD in adults in more than 40 countries¹³; however, the use of these agents in other diseases brings about concerns of malignancy, severe infection, and thrombosis. In the clinical trials for AD, many of these events have not been seen, but the number of patients treated is limited, and longer-term safety assessment is important.^10,11

How will the oral JAK inhibitors be incorporated into care compared to biologic agents such as dupilumab? Tolerance and more serious potential adverse events are concerns, with nausea, headaches, and acneform eruptions being associated with some of the medications, in addition to potential issues with herpes simplex and zoster infections. However, oral JAK inhibitors have the benefit of not requiring injections, something that many patients may prefer, and data show that these drugs generally are associated with a rapid reduction in pruritus and, depending on the drug, very quick and profound effects on objective signs of AD.^10-12 Two head-to-head studies have been completed comparing dupilumab to oral JAK inhibitors in adults: the JADE COMPARE trial examining dupilumab vs abrocitinib¹² and the Heads UP trial comparing dupilumab vs upadacitinib.¹⁴ Compared to dupilumab, higher-dose abrocitinib showed more rapid responses, superiority in itch response, and similarity or superiority in other outcomes depending on the time point of the evaluation. Adverse event profiles differed; for example, abrocitinib was associated with more nausea, acneform eruptions, and herpes zoster, while dupilumab had higher rates of conjunctivitis.¹² Upadacitinib, which was only studied at higher dosing (30 mg daily), showed superiority to dupilumab in itch response and in improvement in AD severity in multiple outcome measures; however, there were increases in serious infections, eczema herpeticum, herpes zoster, and laboratory-related adverse events.¹⁴ Dupilumab has the advantage of studies of extended use along with real-world experience, generally with excellent safety and tolerance other than injection-site reactions and conjunctivitis.⁸ Biologics targeting IL-13—tralokinumab and lebrikizumab—also are to be added to our armamentarium.^15,16 The addition of these agents and JAK inhibitors as new systemic treatment options points to the quickly evolving future of AD treatment for patients with extensive disease.

New topical therapies in development provide even more treatment options. New nonsteroidal topicals include topical JAK inhibitors such as ruxolitinib¹⁷; tapinarof,¹⁸ an aryl hydrocarbon receptor modulator; and phosphodiesterase 4 inhibitors. These agents may be useful either as monotherapy, as studied, potentially without the regional limitations associated with stronger topical corticosteroids, but also should be useful in clinical practice as part of therapeutic regimens with other topical steroid and nonsteroidal agents.

The Microbiome and AD

In addition, research looking at topical microbes as specific interventions that may mediate the microbiome and inflammation of AD are intriguing. A recent phase 1 trial from the University of California San Diego¹⁹ indicated that topical bacteriotherapy directed at decreasing Staphylococcus aureus may provide an impact in AD. Observations by Kong et al²⁰ showed that gram-negative microbiome differences are seen in AD patients compared to unaffected individuals, which has fueled studies showing that Roseomonas mucosa, a gram-negative skin commensal, when applied as a topical live biotherapeutic agent has improved disease severity in children and adults with AD.²¹ Although further studies are underway, these initial data suggest a role for microbiome-modifying therapies as AD treatment.

Chronic Hand Eczema

Chronic hand eczema (CHE), which has considerable overlap with AD in many patients, especially children and adolescents,^22-24 is another area of interesting research. This high-prevalence condition is associated with allergic and irritant contact dermatitis^24-26—conditions that are both considered alternative diagnoses for and exacerbators of AD²⁷—and is a disease process currently being targeted for new therapies. Delgocitinib (NCT04872101, NCT04871711), the novel JAK inhibitor ARQ-252 (NCT04378569), among other topical agents, as well as systemic therapeutics such as gusacitinib (NCT03728504), are in active trials for CHE. Given CHE’s impact on quality of life²⁸ and its overlap with AD, investigation into this disorder can help drive future AD research as well as lead to better knowledge and treatment of CHE.

Final Thoughts

Despite the promising results of these myriad new therapies in AD, there are many factors that influence how and when we use these drugs, including their approval status, FDA labeling, and the ability of patients to access and afford treatment. Additionally, continued study is needed to evaluate the long-term safety and extended efficacy of newer drugs, such as the oral JAK inhibitors. Despite these hurdles, the current landscape of research and development is rapidly evolving. Compared to the many years when only one main group of therapies was a reasonable option for patients, the future of AD treatment looks bright.

Atopic dermatitis (AD) is an incredibly common chronic skin disease, affecting up to 25% of children and 7% of adults in the United States.^1,2 Despite the prevalence of this disease and its impact on patient quality of life, research and scholarly work in AD has been limited until recent years. A PubMed search of articles indexed for MEDLINE using the term atopic dermatitis showed that there were fewer than 500 articles published in 2000 and 965 in 2010; with our more recent acceleration in research, there were 2168 articles published in 2020 and more than 1300 published in just the first half of 2021 (through June). This new research includes insights into the pathogenesis of AD and study of the disease impact and comorbidities as well as an extensive amount of drug development and clinical trial work for new topical and systemic therapies.

New Agents to Treat AD

The 2016 approval of crisaborole,³ a phosphodiesterase 4 inhibitor, followed by the approval of dupilumab, an IL-4 and IL-13 pathway inhibitor and the first biologic agent approved for AD,⁴ ushered in a new age of therapy. We currently are awaiting the incorporation of a new set of topical nonsteroidal agents, oral Janus kinase (JAK) inhibitors, and new biologic agents for AD, several of which have completed phase 3 trials and extended safety evaluations. How these new drugs will impact our standard treatment across the spectrum of care for AD is not yet known.

The emergence of new systemic therapies is timely, as the most used systemic medications previously were oral corticosteroids, despite their use being advised against in standard practice guidelines. Other agents such as methotrexate, cyclosporine, azathioprine, and mycophenolate are discussed in the literature and AD treatment guidelines as being potentially useful, though absence of US Food and Drug Administration (FDA) approval and the need for frequent laboratory monitoring, as well as drug-specific side effects and an increased risk of infection, limit their use in the United States, especially in pediatric and adolescent populations.⁵

The approval of dupilumab as a systemic therapy—initially for adults and subsequently for teenagers (12–17 years of age) and then children (6–11 years of age)—has markedly influenced the standard of care for moderate to severe AD. This agent has been shown to have a considerable impact on disease severity and quality of life, with a good safety profile and the added benefit of not requiring continuous (or any) laboratory monitoring.^6-8 Ongoing studies of dupilumab in children (ClinicalTrials.gov identifiers NCT02612454, NCT03346434), including those younger than 1 year,⁹ raise the question of how commonly this medication might be incorporated into care across the entire age spectrum of patients with AD. What standards will there be for assessment of severity, disease impact, and persistence to warrant use in younger ages? Will early treatment with novel systemic agents change the overall course of the disease and minimize the development of comorbidities? The answers to these questions remain to be seen.

JAK Inhibitors for AD
Additional novel therapeutics currently are undergoing studies for treatment of AD, most notably the oral JAK inhibitors upadacitinib,¹⁰ baricitinib,¹¹ and abrocitinib.¹² Each of these agents has completed phase 3 trials for AD. Two of these agents—upadacitinib and baricitinib—have prior FDA approval for use in other disease states. Of note, baricitinib is already approved for treatment of moderate to severe AD in adults in more than 40 countries¹³; however, the use of these agents in other diseases brings about concerns of malignancy, severe infection, and thrombosis. In the clinical trials for AD, many of these events have not been seen, but the number of patients treated is limited, and longer-term safety assessment is important.^10,11

How will the oral JAK inhibitors be incorporated into care compared to biologic agents such as dupilumab? Tolerance and more serious potential adverse events are concerns, with nausea, headaches, and acneform eruptions being associated with some of the medications, in addition to potential issues with herpes simplex and zoster infections. However, oral JAK inhibitors have the benefit of not requiring injections, something that many patients may prefer, and data show that these drugs generally are associated with a rapid reduction in pruritus and, depending on the drug, very quick and profound effects on objective signs of AD.^10-12 Two head-to-head studies have been completed comparing dupilumab to oral JAK inhibitors in adults: the JADE COMPARE trial examining dupilumab vs abrocitinib¹² and the Heads UP trial comparing dupilumab vs upadacitinib.¹⁴ Compared to dupilumab, higher-dose abrocitinib showed more rapid responses, superiority in itch response, and similarity or superiority in other outcomes depending on the time point of the evaluation. Adverse event profiles differed; for example, abrocitinib was associated with more nausea, acneform eruptions, and herpes zoster, while dupilumab had higher rates of conjunctivitis.¹² Upadacitinib, which was only studied at higher dosing (30 mg daily), showed superiority to dupilumab in itch response and in improvement in AD severity in multiple outcome measures; however, there were increases in serious infections, eczema herpeticum, herpes zoster, and laboratory-related adverse events.¹⁴ Dupilumab has the advantage of studies of extended use along with real-world experience, generally with excellent safety and tolerance other than injection-site reactions and conjunctivitis.⁸ Biologics targeting IL-13—tralokinumab and lebrikizumab—also are to be added to our armamentarium.^15,16 The addition of these agents and JAK inhibitors as new systemic treatment options points to the quickly evolving future of AD treatment for patients with extensive disease.

New topical therapies in development provide even more treatment options. New nonsteroidal topicals include topical JAK inhibitors such as ruxolitinib¹⁷; tapinarof,¹⁸ an aryl hydrocarbon receptor modulator; and phosphodiesterase 4 inhibitors. These agents may be useful either as monotherapy, as studied, potentially without the regional limitations associated with stronger topical corticosteroids, but also should be useful in clinical practice as part of therapeutic regimens with other topical steroid and nonsteroidal agents.

The Microbiome and AD

In addition, research looking at topical microbes as specific interventions that may mediate the microbiome and inflammation of AD are intriguing. A recent phase 1 trial from the University of California San Diego¹⁹ indicated that topical bacteriotherapy directed at decreasing Staphylococcus aureus may provide an impact in AD. Observations by Kong et al²⁰ showed that gram-negative microbiome differences are seen in AD patients compared to unaffected individuals, which has fueled studies showing that Roseomonas mucosa, a gram-negative skin commensal, when applied as a topical live biotherapeutic agent has improved disease severity in children and adults with AD.²¹ Although further studies are underway, these initial data suggest a role for microbiome-modifying therapies as AD treatment.

Chronic Hand Eczema

Chronic hand eczema (CHE), which has considerable overlap with AD in many patients, especially children and adolescents,^22-24 is another area of interesting research. This high-prevalence condition is associated with allergic and irritant contact dermatitis^24-26—conditions that are both considered alternative diagnoses for and exacerbators of AD²⁷—and is a disease process currently being targeted for new therapies. Delgocitinib (NCT04872101, NCT04871711), the novel JAK inhibitor ARQ-252 (NCT04378569), among other topical agents, as well as systemic therapeutics such as gusacitinib (NCT03728504), are in active trials for CHE. Given CHE’s impact on quality of life²⁸ and its overlap with AD, investigation into this disorder can help drive future AD research as well as lead to better knowledge and treatment of CHE.

Final Thoughts

Despite the promising results of these myriad new therapies in AD, there are many factors that influence how and when we use these drugs, including their approval status, FDA labeling, and the ability of patients to access and afford treatment. Additionally, continued study is needed to evaluate the long-term safety and extended efficacy of newer drugs, such as the oral JAK inhibitors. Despite these hurdles, the current landscape of research and development is rapidly evolving. Compared to the many years when only one main group of therapies was a reasonable option for patients, the future of AD treatment looks bright.

Atopic dermatitis (AD) is an incredibly common chronic skin disease, affecting up to 25% of children and 7% of adults in the United States.^1,2 Despite the prevalence of this disease and its impact on patient quality of life, research and scholarly work in AD has been limited until recent years. A PubMed search of articles indexed for MEDLINE using the term atopic dermatitis showed that there were fewer than 500 articles published in 2000 and 965 in 2010; with our more recent acceleration in research, there were 2168 articles published in 2020 and more than 1300 published in just the first half of 2021 (through June). This new research includes insights into the pathogenesis of AD and study of the disease impact and comorbidities as well as an extensive amount of drug development and clinical trial work for new topical and systemic therapies.

New Agents to Treat AD

The 2016 approval of crisaborole,³ a phosphodiesterase 4 inhibitor, followed by the approval of dupilumab, an IL-4 and IL-13 pathway inhibitor and the first biologic agent approved for AD,⁴ ushered in a new age of therapy. We currently are awaiting the incorporation of a new set of topical nonsteroidal agents, oral Janus kinase (JAK) inhibitors, and new biologic agents for AD, several of which have completed phase 3 trials and extended safety evaluations. How these new drugs will impact our standard treatment across the spectrum of care for AD is not yet known.

The emergence of new systemic therapies is timely, as the most used systemic medications previously were oral corticosteroids, despite their use being advised against in standard practice guidelines. Other agents such as methotrexate, cyclosporine, azathioprine, and mycophenolate are discussed in the literature and AD treatment guidelines as being potentially useful, though absence of US Food and Drug Administration (FDA) approval and the need for frequent laboratory monitoring, as well as drug-specific side effects and an increased risk of infection, limit their use in the United States, especially in pediatric and adolescent populations.⁵

The approval of dupilumab as a systemic therapy—initially for adults and subsequently for teenagers (12–17 years of age) and then children (6–11 years of age)—has markedly influenced the standard of care for moderate to severe AD. This agent has been shown to have a considerable impact on disease severity and quality of life, with a good safety profile and the added benefit of not requiring continuous (or any) laboratory monitoring.^6-8 Ongoing studies of dupilumab in children (ClinicalTrials.gov identifiers NCT02612454, NCT03346434), including those younger than 1 year,⁹ raise the question of how commonly this medication might be incorporated into care across the entire age spectrum of patients with AD. What standards will there be for assessment of severity, disease impact, and persistence to warrant use in younger ages? Will early treatment with novel systemic agents change the overall course of the disease and minimize the development of comorbidities? The answers to these questions remain to be seen.

JAK Inhibitors for AD
Additional novel therapeutics currently are undergoing studies for treatment of AD, most notably the oral JAK inhibitors upadacitinib,¹⁰ baricitinib,¹¹ and abrocitinib.¹² Each of these agents has completed phase 3 trials for AD. Two of these agents—upadacitinib and baricitinib—have prior FDA approval for use in other disease states. Of note, baricitinib is already approved for treatment of moderate to severe AD in adults in more than 40 countries¹³; however, the use of these agents in other diseases brings about concerns of malignancy, severe infection, and thrombosis. In the clinical trials for AD, many of these events have not been seen, but the number of patients treated is limited, and longer-term safety assessment is important.^10,11

How will the oral JAK inhibitors be incorporated into care compared to biologic agents such as dupilumab? Tolerance and more serious potential adverse events are concerns, with nausea, headaches, and acneform eruptions being associated with some of the medications, in addition to potential issues with herpes simplex and zoster infections. However, oral JAK inhibitors have the benefit of not requiring injections, something that many patients may prefer, and data show that these drugs generally are associated with a rapid reduction in pruritus and, depending on the drug, very quick and profound effects on objective signs of AD.^10-12 Two head-to-head studies have been completed comparing dupilumab to oral JAK inhibitors in adults: the JADE COMPARE trial examining dupilumab vs abrocitinib¹² and the Heads UP trial comparing dupilumab vs upadacitinib.¹⁴ Compared to dupilumab, higher-dose abrocitinib showed more rapid responses, superiority in itch response, and similarity or superiority in other outcomes depending on the time point of the evaluation. Adverse event profiles differed; for example, abrocitinib was associated with more nausea, acneform eruptions, and herpes zoster, while dupilumab had higher rates of conjunctivitis.¹² Upadacitinib, which was only studied at higher dosing (30 mg daily), showed superiority to dupilumab in itch response and in improvement in AD severity in multiple outcome measures; however, there were increases in serious infections, eczema herpeticum, herpes zoster, and laboratory-related adverse events.¹⁴ Dupilumab has the advantage of studies of extended use along with real-world experience, generally with excellent safety and tolerance other than injection-site reactions and conjunctivitis.⁸ Biologics targeting IL-13—tralokinumab and lebrikizumab—also are to be added to our armamentarium.^15,16 The addition of these agents and JAK inhibitors as new systemic treatment options points to the quickly evolving future of AD treatment for patients with extensive disease.

New topical therapies in development provide even more treatment options. New nonsteroidal topicals include topical JAK inhibitors such as ruxolitinib¹⁷; tapinarof,¹⁸ an aryl hydrocarbon receptor modulator; and phosphodiesterase 4 inhibitors. These agents may be useful either as monotherapy, as studied, potentially without the regional limitations associated with stronger topical corticosteroids, but also should be useful in clinical practice as part of therapeutic regimens with other topical steroid and nonsteroidal agents.

The Microbiome and AD

In addition, research looking at topical microbes as specific interventions that may mediate the microbiome and inflammation of AD are intriguing. A recent phase 1 trial from the University of California San Diego¹⁹ indicated that topical bacteriotherapy directed at decreasing Staphylococcus aureus may provide an impact in AD. Observations by Kong et al²⁰ showed that gram-negative microbiome differences are seen in AD patients compared to unaffected individuals, which has fueled studies showing that Roseomonas mucosa, a gram-negative skin commensal, when applied as a topical live biotherapeutic agent has improved disease severity in children and adults with AD.²¹ Although further studies are underway, these initial data suggest a role for microbiome-modifying therapies as AD treatment.

Chronic Hand Eczema

Chronic hand eczema (CHE), which has considerable overlap with AD in many patients, especially children and adolescents,^22-24 is another area of interesting research. This high-prevalence condition is associated with allergic and irritant contact dermatitis^24-26—conditions that are both considered alternative diagnoses for and exacerbators of AD²⁷—and is a disease process currently being targeted for new therapies. Delgocitinib (NCT04872101, NCT04871711), the novel JAK inhibitor ARQ-252 (NCT04378569), among other topical agents, as well as systemic therapeutics such as gusacitinib (NCT03728504), are in active trials for CHE. Given CHE’s impact on quality of life²⁸ and its overlap with AD, investigation into this disorder can help drive future AD research as well as lead to better knowledge and treatment of CHE.

Final Thoughts

Despite the promising results of these myriad new therapies in AD, there are many factors that influence how and when we use these drugs, including their approval status, FDA labeling, and the ability of patients to access and afford treatment. Additionally, continued study is needed to evaluate the long-term safety and extended efficacy of newer drugs, such as the oral JAK inhibitors. Despite these hurdles, the current landscape of research and development is rapidly evolving. Compared to the many years when only one main group of therapies was a reasonable option for patients, the future of AD treatment looks bright.