Contact Dermatitis

In a survey of products labeled as hypoallergenic for children, about half of shampoos and almost 44% of soaps contained cocamidopropyl betaine (CAPB), a suspected sensitizer for hypersensitivity reactions in people with atopic dermatitis (AD) and allergic contact dermatitis, according to a research letter in the Journal of the American Academy of Dermatology.

Pirotehnik/iStock/Getty Images

In the letter, the authors, Reid W. Collis, of Washington University in St. Louis, and David M. Sheinbein, MD, of the division of dermatology at the university, referred to a previous study showing an association between contact sensitivity with CAPB and people with a history of AD. This was supported by the results of their own recent study in pediatric patients, they wrote, which found that reactions to CAPB were “exclusively” in patients with AD.

In the survey, they looked at children’s shampoo and soap products available on online databases of six of the biggest retailers, and analyzed the top 20 best-selling products for each retailer in 2018. Of the unique products, CAPB was found to be an ingredient in 52% (39 of 75) of the shampoos and 44% (29 of 66) of the soap products. But each of these products “contained the term ‘hypoallergenic; on the product itself or in the product’s description,” they noted.

“CAPB is a prevalent sensitizer in pediatric patients and should be avoided in patients with AD,” the investigators wrote. That said, it’s not included among the 35 prevalent allergens in the T.R.U.E. test, and they recommended that pediatricians and dermatologists “be aware of common products containing CAPB when counseling patients about their product choices,” considering that CAPB sensitivity is more likely in patients with AD.

The study had no funding source, and the authors had no disclosures.

[email protected]

SOURCE: Cho SI et al. J Am Acad Dermatol. 2020 May. doi: 10.1016/j.jaad.2019.12.036.

In a survey of products labeled as hypoallergenic for children, about half of shampoos and almost 44% of soaps contained cocamidopropyl betaine (CAPB), a suspected sensitizer for hypersensitivity reactions in people with atopic dermatitis (AD) and allergic contact dermatitis, according to a research letter in the Journal of the American Academy of Dermatology.

Pirotehnik/iStock/Getty Images

In the letter, the authors, Reid W. Collis, of Washington University in St. Louis, and David M. Sheinbein, MD, of the division of dermatology at the university, referred to a previous study showing an association between contact sensitivity with CAPB and people with a history of AD. This was supported by the results of their own recent study in pediatric patients, they wrote, which found that reactions to CAPB were “exclusively” in patients with AD.

In the survey, they looked at children’s shampoo and soap products available on online databases of six of the biggest retailers, and analyzed the top 20 best-selling products for each retailer in 2018. Of the unique products, CAPB was found to be an ingredient in 52% (39 of 75) of the shampoos and 44% (29 of 66) of the soap products. But each of these products “contained the term ‘hypoallergenic; on the product itself or in the product’s description,” they noted.

“CAPB is a prevalent sensitizer in pediatric patients and should be avoided in patients with AD,” the investigators wrote. That said, it’s not included among the 35 prevalent allergens in the T.R.U.E. test, and they recommended that pediatricians and dermatologists “be aware of common products containing CAPB when counseling patients about their product choices,” considering that CAPB sensitivity is more likely in patients with AD.

The study had no funding source, and the authors had no disclosures.

[email protected]

SOURCE: Cho SI et al. J Am Acad Dermatol. 2020 May. doi: 10.1016/j.jaad.2019.12.036.

In a survey of products labeled as hypoallergenic for children, about half of shampoos and almost 44% of soaps contained cocamidopropyl betaine (CAPB), a suspected sensitizer for hypersensitivity reactions in people with atopic dermatitis (AD) and allergic contact dermatitis, according to a research letter in the Journal of the American Academy of Dermatology.

Pirotehnik/iStock/Getty Images

In the letter, the authors, Reid W. Collis, of Washington University in St. Louis, and David M. Sheinbein, MD, of the division of dermatology at the university, referred to a previous study showing an association between contact sensitivity with CAPB and people with a history of AD. This was supported by the results of their own recent study in pediatric patients, they wrote, which found that reactions to CAPB were “exclusively” in patients with AD.

In the survey, they looked at children’s shampoo and soap products available on online databases of six of the biggest retailers, and analyzed the top 20 best-selling products for each retailer in 2018. Of the unique products, CAPB was found to be an ingredient in 52% (39 of 75) of the shampoos and 44% (29 of 66) of the soap products. But each of these products “contained the term ‘hypoallergenic; on the product itself or in the product’s description,” they noted.

“CAPB is a prevalent sensitizer in pediatric patients and should be avoided in patients with AD,” the investigators wrote. That said, it’s not included among the 35 prevalent allergens in the T.R.U.E. test, and they recommended that pediatricians and dermatologists “be aware of common products containing CAPB when counseling patients about their product choices,” considering that CAPB sensitivity is more likely in patients with AD.

The study had no funding source, and the authors had no disclosures.

[email protected]

SOURCE: Cho SI et al. J Am Acad Dermatol. 2020 May. doi: 10.1016/j.jaad.2019.12.036.

The Diagnosis: Fiddler's Neck 

A thorough patient history revealed that the patient was retired and played violin regularly in the local orchestra. Fiddler's neck, or violin hickey, is an uncommon physical examination finding and often is considered a badge of honor by musicians who develop it. Fiddler's neck is a hobby-related callus seen in highly dedicated violin and viola players, and in some circles, it is known as a mark of greatness. In one instance, members of the public were asked to display a violin hickey before they were allowed to play a $3.5 million violin on public display in London, England.¹ Fiddler's neck is a benign submandibular lesion caused by pressure and friction on the skin from extensive time spent playing the instrument. The primary cause is thought to be mechanical, but it is not fully understood why the lesion occurs in some musicians and not others, regardless of playing time.¹ This submandibular fiddler's neck is distinct from a similarly named supraclavicular lesion, which represents an allergic contact dermatitis to the nickel bracket of the instrument's chin rest and presents with eczematous scale and/or vesicles.^2,3 Submandibular fiddler's neck presents with some combination of erythema, edema, lichenification, and scarring just below the angle of the jaw. Occasionally, papules, pustules, and even cyst formation may be noted. Lesions are sometimes mistaken for malignancy or lymphedema. Therefore, a thorough history and clinical expertise are important, as surgical excision should be avoided.²  

Depending on presentation, the differential diagnosis also may include malignant melanoma due to irregular pigmentation, branchial cleft cyst or sialolithiasis due to location and texture, or a tumor of the salivary gland. 

Management of fiddler's neck may include topical steroids, neck or instrument padding, or decreased playing time. However, the lesion often is worn with pride, seen as a testament to the musician's dedication, and reassurance generally is most appropriate.¹  

The Diagnosis: Fiddler's Neck 

A thorough patient history revealed that the patient was retired and played violin regularly in the local orchestra. Fiddler's neck, or violin hickey, is an uncommon physical examination finding and often is considered a badge of honor by musicians who develop it. Fiddler's neck is a hobby-related callus seen in highly dedicated violin and viola players, and in some circles, it is known as a mark of greatness. In one instance, members of the public were asked to display a violin hickey before they were allowed to play a $3.5 million violin on public display in London, England.¹ Fiddler's neck is a benign submandibular lesion caused by pressure and friction on the skin from extensive time spent playing the instrument. The primary cause is thought to be mechanical, but it is not fully understood why the lesion occurs in some musicians and not others, regardless of playing time.¹ This submandibular fiddler's neck is distinct from a similarly named supraclavicular lesion, which represents an allergic contact dermatitis to the nickel bracket of the instrument's chin rest and presents with eczematous scale and/or vesicles.^2,3 Submandibular fiddler's neck presents with some combination of erythema, edema, lichenification, and scarring just below the angle of the jaw. Occasionally, papules, pustules, and even cyst formation may be noted. Lesions are sometimes mistaken for malignancy or lymphedema. Therefore, a thorough history and clinical expertise are important, as surgical excision should be avoided.²  

Depending on presentation, the differential diagnosis also may include malignant melanoma due to irregular pigmentation, branchial cleft cyst or sialolithiasis due to location and texture, or a tumor of the salivary gland. 

Management of fiddler's neck may include topical steroids, neck or instrument padding, or decreased playing time. However, the lesion often is worn with pride, seen as a testament to the musician's dedication, and reassurance generally is most appropriate.¹  

The Diagnosis: Fiddler's Neck 

A thorough patient history revealed that the patient was retired and played violin regularly in the local orchestra. Fiddler's neck, or violin hickey, is an uncommon physical examination finding and often is considered a badge of honor by musicians who develop it. Fiddler's neck is a hobby-related callus seen in highly dedicated violin and viola players, and in some circles, it is known as a mark of greatness. In one instance, members of the public were asked to display a violin hickey before they were allowed to play a $3.5 million violin on public display in London, England.¹ Fiddler's neck is a benign submandibular lesion caused by pressure and friction on the skin from extensive time spent playing the instrument. The primary cause is thought to be mechanical, but it is not fully understood why the lesion occurs in some musicians and not others, regardless of playing time.¹ This submandibular fiddler's neck is distinct from a similarly named supraclavicular lesion, which represents an allergic contact dermatitis to the nickel bracket of the instrument's chin rest and presents with eczematous scale and/or vesicles.^2,3 Submandibular fiddler's neck presents with some combination of erythema, edema, lichenification, and scarring just below the angle of the jaw. Occasionally, papules, pustules, and even cyst formation may be noted. Lesions are sometimes mistaken for malignancy or lymphedema. Therefore, a thorough history and clinical expertise are important, as surgical excision should be avoided.²  

Depending on presentation, the differential diagnosis also may include malignant melanoma due to irregular pigmentation, branchial cleft cyst or sialolithiasis due to location and texture, or a tumor of the salivary gland. 

Management of fiddler's neck may include topical steroids, neck or instrument padding, or decreased playing time. However, the lesion often is worn with pride, seen as a testament to the musician's dedication, and reassurance generally is most appropriate.¹  

To the Editor:

Phytophotodermatitis is common in dermatology during the summer months, especially in individuals who spend time outdoors; however, identification of the offending plant can be challenging. We report a case of phytophotodermatitis in which the causative plant, common rue, was not identified until it was revealed that the patient was a butterfly enthusiast.

A 60-year-old woman presented to the outpatient dermatology clinic in late summer for a routine skin examination. An eruption was noted over the right thigh and knee that had first appeared approximately 2 weeks prior. The rash started as pruritic blisters but gradually progressed to erythema and then eventually to brown markings, which were observed at the current presentation. Physical examination revealed hyperpigmented, brown, streaky, linear patches and plaques over the right thigh, knee, and lower leg (Figure). When asked about her hobbies, the patient reported an affinity for butterflies and noted that she attracts them with specific species of plants in her garden. She recalled recently planting the herb of grace, or common rue, to attract the giant swallowtail butterfly (Papilio cresphontes). Upon further inquiry, she remembered working in the garden on her knees and digging up roots near the common rue plant while wearing shorts approximately 2 weeks prior to the current presentation. Given the streaky linear pattern of the eruption along with recent sun exposure and exposure to the common rue plant, a diagnosis of phytophotodermatitis was made. No further treatment was sought, as the eruption was not bothersome to her. She was intrigued that the common rue plant had caused the dermatitis and planned on taking proper precautions when working near the plant in the future.

This case illustrates a unique perspective of phytophotodermatitis, as butterfly enthusiasm is not commonly reported in association with the common rue plant with respect to phytophotodermatitis. This case underscores the importance of inquiring about patients’ professions and hobbies, both in dermatology and other specialties.

To the Editor:

Phytophotodermatitis is common in dermatology during the summer months, especially in individuals who spend time outdoors; however, identification of the offending plant can be challenging. We report a case of phytophotodermatitis in which the causative plant, common rue, was not identified until it was revealed that the patient was a butterfly enthusiast.

A 60-year-old woman presented to the outpatient dermatology clinic in late summer for a routine skin examination. An eruption was noted over the right thigh and knee that had first appeared approximately 2 weeks prior. The rash started as pruritic blisters but gradually progressed to erythema and then eventually to brown markings, which were observed at the current presentation. Physical examination revealed hyperpigmented, brown, streaky, linear patches and plaques over the right thigh, knee, and lower leg (Figure). When asked about her hobbies, the patient reported an affinity for butterflies and noted that she attracts them with specific species of plants in her garden. She recalled recently planting the herb of grace, or common rue, to attract the giant swallowtail butterfly (Papilio cresphontes). Upon further inquiry, she remembered working in the garden on her knees and digging up roots near the common rue plant while wearing shorts approximately 2 weeks prior to the current presentation. Given the streaky linear pattern of the eruption along with recent sun exposure and exposure to the common rue plant, a diagnosis of phytophotodermatitis was made. No further treatment was sought, as the eruption was not bothersome to her. She was intrigued that the common rue plant had caused the dermatitis and planned on taking proper precautions when working near the plant in the future.

This case illustrates a unique perspective of phytophotodermatitis, as butterfly enthusiasm is not commonly reported in association with the common rue plant with respect to phytophotodermatitis. This case underscores the importance of inquiring about patients’ professions and hobbies, both in dermatology and other specialties.

To the Editor:

Phytophotodermatitis is common in dermatology during the summer months, especially in individuals who spend time outdoors; however, identification of the offending plant can be challenging. We report a case of phytophotodermatitis in which the causative plant, common rue, was not identified until it was revealed that the patient was a butterfly enthusiast.

A 60-year-old woman presented to the outpatient dermatology clinic in late summer for a routine skin examination. An eruption was noted over the right thigh and knee that had first appeared approximately 2 weeks prior. The rash started as pruritic blisters but gradually progressed to erythema and then eventually to brown markings, which were observed at the current presentation. Physical examination revealed hyperpigmented, brown, streaky, linear patches and plaques over the right thigh, knee, and lower leg (Figure). When asked about her hobbies, the patient reported an affinity for butterflies and noted that she attracts them with specific species of plants in her garden. She recalled recently planting the herb of grace, or common rue, to attract the giant swallowtail butterfly (Papilio cresphontes). Upon further inquiry, she remembered working in the garden on her knees and digging up roots near the common rue plant while wearing shorts approximately 2 weeks prior to the current presentation. Given the streaky linear pattern of the eruption along with recent sun exposure and exposure to the common rue plant, a diagnosis of phytophotodermatitis was made. No further treatment was sought, as the eruption was not bothersome to her. She was intrigued that the common rue plant had caused the dermatitis and planned on taking proper precautions when working near the plant in the future.

This case illustrates a unique perspective of phytophotodermatitis, as butterfly enthusiasm is not commonly reported in association with the common rue plant with respect to phytophotodermatitis. This case underscores the importance of inquiring about patients’ professions and hobbies, both in dermatology and other specialties.

What is an essential oil?

An essential oil (EO) is defined by the International Organization for Standardization as a ‘‘product obtained from a natural raw material of plant origin, by steam distillation, by mechanical processes from the epicarp of citrus fruits, or by dry distillation, after separation of the aqueous phase—if any—by physical processes.’’¹ Steam distillation is the primary method used for the production of commercial EOs,² and believe it or not, most EOs contain 100 to 250 individual chemical components.³

The term essential oil often is incorrectly used for a variety of products obtained from plant material by methods other than distillation or cold-pressing, such as extraction. Products that are obtained via the extraction method include absolutes found in fine fragrances; hydrolates such as rose water; concretes such as jasmine or violet leaves; and vegetable oils including olive oil, coconut oil, and sesame oil.² These products are not true EOs.

Where do EOs come from?

Essential oils are produced in many countries around the world.⁴ Individual oils may be obtained from species of different plants, from different parts of the same plant, or from various cultivars (plants selectively bred to obtain desirable levels of chemical constituents such as monoterpenes or sesquiterpenes and biochemical properties such as antibacterial or antioxidant activities).^3,5 It is estimated that EOs can be obtained from approximately 30,000 plant species, but only 150 EOs are produced commercially.^2,6

Why are people using EOs? What is their claim to fame?

Essential oils are employed by the flavor, food (eg, soft drinks, milk, candies, chocolate, meats, sausages, alcoholic beverages, spices, herbs, tea, preservatives, animal foods), fragrance, cosmetic, tobacco, and pharmaceutical industries. They also are used in household products (eg, detergents, fabric softeners, air fresheners, candles, incense) and for medicinal purposes (eg, folk and traditional medicine, phytotherapy, balneotherapy, aromatherapy).² The oils usually are applied to the skin but also can be administered orally, inhaled, diffused through the air, or used by other means.⁴ One 2019 survey of Minnesota State Fair attendees (N=282) found the most common reasons for using EOs were a desire for alternative treatments (53.4%), the opinion that EOs are safer than traditional therapies (47.6%), and/or failure of standard medical treatments (10.7%). The survey results also indicated that 46.7% of EO users utilized EOs to treat medical conditions or symptoms.⁷ Of note, review of the website of an international company that produces EOs confirmed that EOs are marketed not only for adults but also for children to help them concentrate,⁸ sleep,⁹ improve the appearance of their skin,¹⁰ soothe upset stomachs,¹¹ and decrease sniffles due to colds.¹²

Why are people selling EOs to family and friends? They must be making major bucks!

In general, the cost of EOs depends on the complexity of cultivated plant species; the mode of harvesting, which is sometimes done by hand; and the yield of oil. Prices range from $4.50 to an incredible $150,000 per kilogram.² On average, one bottle containing 5 to 15 mL of an EO or oil blend can cost anywhere from $7 to $251.¹³ In the United States, the consumer EO market is partially composed of multilevel/network marketing companies in which direct consumer sales occur via a hierarchy of individual distributors. Goodier et al⁷ found that 36.4% of participants who obtained EOs from family and friends purchased them through multilevel/network marketing companies. In 2018, individual distributors of an international EO-producing company made on average anywhere from $4 to as much as $1.54 million annually by selling the company’s EO products and enrolling additional members/individual distributors to purchase or sell the company’s EO products.¹⁴

Sometimes EOs are described as natural and pure, but are they really?

Just because a product is labeled as “pure” or “natural” does not ensure that it is a good-quality EO. Organically produced (ie, grown without the use of herbicides or pesticides) plant material can include up to 30% of extraneous herbs and weeds, which can change the composition of the oil.²

Lesser-quality EOs are the result of adulteration, contamination, inadequate oil production, or aging.² Adulteration (eg, cutting, stretching, bouquetting) occurs when foreign substances are introduced into pure EOs for the benefit of a higher profit; to ensure a sufficient supply of oils; or to meet demands for cheaper oils by “stretching” a more expensive, pure oil by combining with a cheaper, less pure oil. Inadequate oil production leading to lower-quality oils can occur when a biomass is incorrectly distilled, either from too much steam or temperatures that are too high or due to lack of adequate cooling units. Aging occurs when the oils are not stored properly, resulting in a change in the chemical composition due to esterification, reduction, and oxidization of chemicals, which leads to the formation of peroxides and hydroperoxides that can be contact allergens.¹⁵

Can patients develop contact allergies to EOs?

The short answer is yes! Contact allergy to almost 80 EOs has been reported,¹⁵ including tea tree oil,^16,17 ylang-ylang oil,^17,18 lavender oil, peppermint oil,¹⁸ jasmine absolute,¹⁷ geranium oil, rose oil,¹⁸ turpentine oil,^19,20 and sandalwood oil.¹⁸ The recent increased prevalence of allergic reactions to EOs likely is due to increased consumer use as well as increased detection from availability of commercial patch-test preparations.

Essential oils have many common ingredients. De Groot and Schmidt³ documented that 14 of 23 chemicals present in more than 80% of EOs have been reported to cause contact allergy. Interestingly, allergic patients often react to more than one EO, which may be explained by the many shared chemical components in EOs.

Essential oils are “natural” so they must be safe?

In general, most safety profiles are good, but rare toxic reactions from EOs have been observed.⁴ A recent Australian study reviewed EO exposure calls to the New South Wales Poisons Information Centre.²¹ The majority of EO poisonings were accidental or the result of therapeutic error such as mistaking EOs for liquid pharmaceuticals. Additionally, this study found that from July 2014 to June 2018, there was a 5% increase in the number of calls per year. More than half of EO poisoning calls involved children, with toddlers being the most frequent cases, suggesting the need for child-resistant top closures. The most frequently involved EOs in poisonings were eucalyptus (46.4% [n=2049]), tea tree (17% [n=749]), lavender (6.1% [n=271]), clove (4.1% [n=179]), and peppermint (3.5% [n=154]).²¹ Essential oils do not come without potential pitfalls.

What is the clinical presentation and workup?

The workup of EO allergic contact dermatitis begins with obtaining a history to evaluate for use of EO diffusers, perfumes, hygiene products, cosmetics, massage oils, toothpastes, and/or pharmaceutical products. Exploration of potential exposures through occupation, environment, and hobbies also is indicated. Clinical presentation is dependent on the mechanism of exposure. Contact allergy may result from direct application of an allergen to the skin or mucous membranes, contact with a contaminated environmental item (eg, lavender oil on a pillow), contact with EOs used by partners or coworkers (consort dermatitis), airborne exposure (EO diffusers), or systemic exposure (flavorings). Airborne dermatitis from EO diffusers may involve the exposed areas of the face, neck, forearms, arms, behind the earlobes, bilateral eyelids, nasolabial folds, and under the chin. History and clinical presentation can raise suspicion for allergic contact dermatitis, and patch testing is necessary to confirm the diagnosis.

How do we patch test for EO contact allergy?

There are many EOs commercially available for patch testing, and they typically are tested at 2% to 5% concentrations in petrolatum.¹⁵ A North American and European study of 62,354 patch-tested patients found that 7.4% of EO-positive individuals did not react to fragrance allergens in a standard screening series including fragrance mix I, fragrance mix II, and balsam of Peru, highlighting the importance of patch testing with specific EOs.²² Currently, only 3 EOs—tea tree oil, peppermint oil, and ylang-ylang oil—are included in the 2019-2020 North American Contact Dermatitis Group screening series, making supplemental testing for other EOs important if contact allergy is suspected; however, testing the patient’s own products is imperative, as there is strong variability in the composition of EOs. Additionally, aged oils may have been exposed to light, oxygen, or varying temperatures, which could result in the formation of additional allergenic chemicals not present in commercially available preparations.¹⁵ In addition to commercially available allergens, we test patient-provided EOs either as is in semi-open fashion (ie, EOs are applied to patient’s back with a cotton swab, allowed to dry, covered with adhesive tape, and read at the same interval as other patch tests²³) or occasionally dilute them to 1% or 10% (in olive oil or mineral oil).

How should I manage a positive patch-test reaction to EOs?

Patients should avoid relevant EO allergens in their products and environment, which can be easily achieved with the use of the American Contact Dermatitis Society’s Contact Allergen Management Program or similar databases.

Final Interpretation

We are ubiquitously exposed to EOs every day—through the products we use at home, at work, and in our environment. Essential oils make their place in the world by providing sweet-smelling aromas in addition to their alleged therapeutic properties; however, beware, EOs may be the culprit of your next patient’s allergic contact dermatitis.

What is an essential oil?

An essential oil (EO) is defined by the International Organization for Standardization as a ‘‘product obtained from a natural raw material of plant origin, by steam distillation, by mechanical processes from the epicarp of citrus fruits, or by dry distillation, after separation of the aqueous phase—if any—by physical processes.’’¹ Steam distillation is the primary method used for the production of commercial EOs,² and believe it or not, most EOs contain 100 to 250 individual chemical components.³

The term essential oil often is incorrectly used for a variety of products obtained from plant material by methods other than distillation or cold-pressing, such as extraction. Products that are obtained via the extraction method include absolutes found in fine fragrances; hydrolates such as rose water; concretes such as jasmine or violet leaves; and vegetable oils including olive oil, coconut oil, and sesame oil.² These products are not true EOs.

Where do EOs come from?

Essential oils are produced in many countries around the world.⁴ Individual oils may be obtained from species of different plants, from different parts of the same plant, or from various cultivars (plants selectively bred to obtain desirable levels of chemical constituents such as monoterpenes or sesquiterpenes and biochemical properties such as antibacterial or antioxidant activities).^3,5 It is estimated that EOs can be obtained from approximately 30,000 plant species, but only 150 EOs are produced commercially.^2,6

Why are people using EOs? What is their claim to fame?

Essential oils are employed by the flavor, food (eg, soft drinks, milk, candies, chocolate, meats, sausages, alcoholic beverages, spices, herbs, tea, preservatives, animal foods), fragrance, cosmetic, tobacco, and pharmaceutical industries. They also are used in household products (eg, detergents, fabric softeners, air fresheners, candles, incense) and for medicinal purposes (eg, folk and traditional medicine, phytotherapy, balneotherapy, aromatherapy).² The oils usually are applied to the skin but also can be administered orally, inhaled, diffused through the air, or used by other means.⁴ One 2019 survey of Minnesota State Fair attendees (N=282) found the most common reasons for using EOs were a desire for alternative treatments (53.4%), the opinion that EOs are safer than traditional therapies (47.6%), and/or failure of standard medical treatments (10.7%). The survey results also indicated that 46.7% of EO users utilized EOs to treat medical conditions or symptoms.⁷ Of note, review of the website of an international company that produces EOs confirmed that EOs are marketed not only for adults but also for children to help them concentrate,⁸ sleep,⁹ improve the appearance of their skin,¹⁰ soothe upset stomachs,¹¹ and decrease sniffles due to colds.¹²

Why are people selling EOs to family and friends? They must be making major bucks!

In general, the cost of EOs depends on the complexity of cultivated plant species; the mode of harvesting, which is sometimes done by hand; and the yield of oil. Prices range from $4.50 to an incredible $150,000 per kilogram.² On average, one bottle containing 5 to 15 mL of an EO or oil blend can cost anywhere from $7 to $251.¹³ In the United States, the consumer EO market is partially composed of multilevel/network marketing companies in which direct consumer sales occur via a hierarchy of individual distributors. Goodier et al⁷ found that 36.4% of participants who obtained EOs from family and friends purchased them through multilevel/network marketing companies. In 2018, individual distributors of an international EO-producing company made on average anywhere from $4 to as much as $1.54 million annually by selling the company’s EO products and enrolling additional members/individual distributors to purchase or sell the company’s EO products.¹⁴

Sometimes EOs are described as natural and pure, but are they really?

Just because a product is labeled as “pure” or “natural” does not ensure that it is a good-quality EO. Organically produced (ie, grown without the use of herbicides or pesticides) plant material can include up to 30% of extraneous herbs and weeds, which can change the composition of the oil.²

Lesser-quality EOs are the result of adulteration, contamination, inadequate oil production, or aging.² Adulteration (eg, cutting, stretching, bouquetting) occurs when foreign substances are introduced into pure EOs for the benefit of a higher profit; to ensure a sufficient supply of oils; or to meet demands for cheaper oils by “stretching” a more expensive, pure oil by combining with a cheaper, less pure oil. Inadequate oil production leading to lower-quality oils can occur when a biomass is incorrectly distilled, either from too much steam or temperatures that are too high or due to lack of adequate cooling units. Aging occurs when the oils are not stored properly, resulting in a change in the chemical composition due to esterification, reduction, and oxidization of chemicals, which leads to the formation of peroxides and hydroperoxides that can be contact allergens.¹⁵

Can patients develop contact allergies to EOs?

The short answer is yes! Contact allergy to almost 80 EOs has been reported,¹⁵ including tea tree oil,^16,17 ylang-ylang oil,^17,18 lavender oil, peppermint oil,¹⁸ jasmine absolute,¹⁷ geranium oil, rose oil,¹⁸ turpentine oil,^19,20 and sandalwood oil.¹⁸ The recent increased prevalence of allergic reactions to EOs likely is due to increased consumer use as well as increased detection from availability of commercial patch-test preparations.

Essential oils have many common ingredients. De Groot and Schmidt³ documented that 14 of 23 chemicals present in more than 80% of EOs have been reported to cause contact allergy. Interestingly, allergic patients often react to more than one EO, which may be explained by the many shared chemical components in EOs.

Essential oils are “natural” so they must be safe?

In general, most safety profiles are good, but rare toxic reactions from EOs have been observed.⁴ A recent Australian study reviewed EO exposure calls to the New South Wales Poisons Information Centre.²¹ The majority of EO poisonings were accidental or the result of therapeutic error such as mistaking EOs for liquid pharmaceuticals. Additionally, this study found that from July 2014 to June 2018, there was a 5% increase in the number of calls per year. More than half of EO poisoning calls involved children, with toddlers being the most frequent cases, suggesting the need for child-resistant top closures. The most frequently involved EOs in poisonings were eucalyptus (46.4% [n=2049]), tea tree (17% [n=749]), lavender (6.1% [n=271]), clove (4.1% [n=179]), and peppermint (3.5% [n=154]).²¹ Essential oils do not come without potential pitfalls.

What is the clinical presentation and workup?

The workup of EO allergic contact dermatitis begins with obtaining a history to evaluate for use of EO diffusers, perfumes, hygiene products, cosmetics, massage oils, toothpastes, and/or pharmaceutical products. Exploration of potential exposures through occupation, environment, and hobbies also is indicated. Clinical presentation is dependent on the mechanism of exposure. Contact allergy may result from direct application of an allergen to the skin or mucous membranes, contact with a contaminated environmental item (eg, lavender oil on a pillow), contact with EOs used by partners or coworkers (consort dermatitis), airborne exposure (EO diffusers), or systemic exposure (flavorings). Airborne dermatitis from EO diffusers may involve the exposed areas of the face, neck, forearms, arms, behind the earlobes, bilateral eyelids, nasolabial folds, and under the chin. History and clinical presentation can raise suspicion for allergic contact dermatitis, and patch testing is necessary to confirm the diagnosis.

How do we patch test for EO contact allergy?

There are many EOs commercially available for patch testing, and they typically are tested at 2% to 5% concentrations in petrolatum.¹⁵ A North American and European study of 62,354 patch-tested patients found that 7.4% of EO-positive individuals did not react to fragrance allergens in a standard screening series including fragrance mix I, fragrance mix II, and balsam of Peru, highlighting the importance of patch testing with specific EOs.²² Currently, only 3 EOs—tea tree oil, peppermint oil, and ylang-ylang oil—are included in the 2019-2020 North American Contact Dermatitis Group screening series, making supplemental testing for other EOs important if contact allergy is suspected; however, testing the patient’s own products is imperative, as there is strong variability in the composition of EOs. Additionally, aged oils may have been exposed to light, oxygen, or varying temperatures, which could result in the formation of additional allergenic chemicals not present in commercially available preparations.¹⁵ In addition to commercially available allergens, we test patient-provided EOs either as is in semi-open fashion (ie, EOs are applied to patient’s back with a cotton swab, allowed to dry, covered with adhesive tape, and read at the same interval as other patch tests²³) or occasionally dilute them to 1% or 10% (in olive oil or mineral oil).

How should I manage a positive patch-test reaction to EOs?

Patients should avoid relevant EO allergens in their products and environment, which can be easily achieved with the use of the American Contact Dermatitis Society’s Contact Allergen Management Program or similar databases.

Final Interpretation

We are ubiquitously exposed to EOs every day—through the products we use at home, at work, and in our environment. Essential oils make their place in the world by providing sweet-smelling aromas in addition to their alleged therapeutic properties; however, beware, EOs may be the culprit of your next patient’s allergic contact dermatitis.

What is an essential oil?

An essential oil (EO) is defined by the International Organization for Standardization as a ‘‘product obtained from a natural raw material of plant origin, by steam distillation, by mechanical processes from the epicarp of citrus fruits, or by dry distillation, after separation of the aqueous phase—if any—by physical processes.’’¹ Steam distillation is the primary method used for the production of commercial EOs,² and believe it or not, most EOs contain 100 to 250 individual chemical components.³

The term essential oil often is incorrectly used for a variety of products obtained from plant material by methods other than distillation or cold-pressing, such as extraction. Products that are obtained via the extraction method include absolutes found in fine fragrances; hydrolates such as rose water; concretes such as jasmine or violet leaves; and vegetable oils including olive oil, coconut oil, and sesame oil.² These products are not true EOs.

Where do EOs come from?

Essential oils are produced in many countries around the world.⁴ Individual oils may be obtained from species of different plants, from different parts of the same plant, or from various cultivars (plants selectively bred to obtain desirable levels of chemical constituents such as monoterpenes or sesquiterpenes and biochemical properties such as antibacterial or antioxidant activities).^3,5 It is estimated that EOs can be obtained from approximately 30,000 plant species, but only 150 EOs are produced commercially.^2,6

Why are people using EOs? What is their claim to fame?

Essential oils are employed by the flavor, food (eg, soft drinks, milk, candies, chocolate, meats, sausages, alcoholic beverages, spices, herbs, tea, preservatives, animal foods), fragrance, cosmetic, tobacco, and pharmaceutical industries. They also are used in household products (eg, detergents, fabric softeners, air fresheners, candles, incense) and for medicinal purposes (eg, folk and traditional medicine, phytotherapy, balneotherapy, aromatherapy).² The oils usually are applied to the skin but also can be administered orally, inhaled, diffused through the air, or used by other means.⁴ One 2019 survey of Minnesota State Fair attendees (N=282) found the most common reasons for using EOs were a desire for alternative treatments (53.4%), the opinion that EOs are safer than traditional therapies (47.6%), and/or failure of standard medical treatments (10.7%). The survey results also indicated that 46.7% of EO users utilized EOs to treat medical conditions or symptoms.⁷ Of note, review of the website of an international company that produces EOs confirmed that EOs are marketed not only for adults but also for children to help them concentrate,⁸ sleep,⁹ improve the appearance of their skin,¹⁰ soothe upset stomachs,¹¹ and decrease sniffles due to colds.¹²

Why are people selling EOs to family and friends? They must be making major bucks!

In general, the cost of EOs depends on the complexity of cultivated plant species; the mode of harvesting, which is sometimes done by hand; and the yield of oil. Prices range from $4.50 to an incredible $150,000 per kilogram.² On average, one bottle containing 5 to 15 mL of an EO or oil blend can cost anywhere from $7 to $251.¹³ In the United States, the consumer EO market is partially composed of multilevel/network marketing companies in which direct consumer sales occur via a hierarchy of individual distributors. Goodier et al⁷ found that 36.4% of participants who obtained EOs from family and friends purchased them through multilevel/network marketing companies. In 2018, individual distributors of an international EO-producing company made on average anywhere from $4 to as much as $1.54 million annually by selling the company’s EO products and enrolling additional members/individual distributors to purchase or sell the company’s EO products.¹⁴

Sometimes EOs are described as natural and pure, but are they really?

Just because a product is labeled as “pure” or “natural” does not ensure that it is a good-quality EO. Organically produced (ie, grown without the use of herbicides or pesticides) plant material can include up to 30% of extraneous herbs and weeds, which can change the composition of the oil.²

Lesser-quality EOs are the result of adulteration, contamination, inadequate oil production, or aging.² Adulteration (eg, cutting, stretching, bouquetting) occurs when foreign substances are introduced into pure EOs for the benefit of a higher profit; to ensure a sufficient supply of oils; or to meet demands for cheaper oils by “stretching” a more expensive, pure oil by combining with a cheaper, less pure oil. Inadequate oil production leading to lower-quality oils can occur when a biomass is incorrectly distilled, either from too much steam or temperatures that are too high or due to lack of adequate cooling units. Aging occurs when the oils are not stored properly, resulting in a change in the chemical composition due to esterification, reduction, and oxidization of chemicals, which leads to the formation of peroxides and hydroperoxides that can be contact allergens.¹⁵

Can patients develop contact allergies to EOs?

The short answer is yes! Contact allergy to almost 80 EOs has been reported,¹⁵ including tea tree oil,^16,17 ylang-ylang oil,^17,18 lavender oil, peppermint oil,¹⁸ jasmine absolute,¹⁷ geranium oil, rose oil,¹⁸ turpentine oil,^19,20 and sandalwood oil.¹⁸ The recent increased prevalence of allergic reactions to EOs likely is due to increased consumer use as well as increased detection from availability of commercial patch-test preparations.

Essential oils have many common ingredients. De Groot and Schmidt³ documented that 14 of 23 chemicals present in more than 80% of EOs have been reported to cause contact allergy. Interestingly, allergic patients often react to more than one EO, which may be explained by the many shared chemical components in EOs.

Essential oils are “natural” so they must be safe?

In general, most safety profiles are good, but rare toxic reactions from EOs have been observed.⁴ A recent Australian study reviewed EO exposure calls to the New South Wales Poisons Information Centre.²¹ The majority of EO poisonings were accidental or the result of therapeutic error such as mistaking EOs for liquid pharmaceuticals. Additionally, this study found that from July 2014 to June 2018, there was a 5% increase in the number of calls per year. More than half of EO poisoning calls involved children, with toddlers being the most frequent cases, suggesting the need for child-resistant top closures. The most frequently involved EOs in poisonings were eucalyptus (46.4% [n=2049]), tea tree (17% [n=749]), lavender (6.1% [n=271]), clove (4.1% [n=179]), and peppermint (3.5% [n=154]).²¹ Essential oils do not come without potential pitfalls.

What is the clinical presentation and workup?

The workup of EO allergic contact dermatitis begins with obtaining a history to evaluate for use of EO diffusers, perfumes, hygiene products, cosmetics, massage oils, toothpastes, and/or pharmaceutical products. Exploration of potential exposures through occupation, environment, and hobbies also is indicated. Clinical presentation is dependent on the mechanism of exposure. Contact allergy may result from direct application of an allergen to the skin or mucous membranes, contact with a contaminated environmental item (eg, lavender oil on a pillow), contact with EOs used by partners or coworkers (consort dermatitis), airborne exposure (EO diffusers), or systemic exposure (flavorings). Airborne dermatitis from EO diffusers may involve the exposed areas of the face, neck, forearms, arms, behind the earlobes, bilateral eyelids, nasolabial folds, and under the chin. History and clinical presentation can raise suspicion for allergic contact dermatitis, and patch testing is necessary to confirm the diagnosis.

How do we patch test for EO contact allergy?

There are many EOs commercially available for patch testing, and they typically are tested at 2% to 5% concentrations in petrolatum.¹⁵ A North American and European study of 62,354 patch-tested patients found that 7.4% of EO-positive individuals did not react to fragrance allergens in a standard screening series including fragrance mix I, fragrance mix II, and balsam of Peru, highlighting the importance of patch testing with specific EOs.²² Currently, only 3 EOs—tea tree oil, peppermint oil, and ylang-ylang oil—are included in the 2019-2020 North American Contact Dermatitis Group screening series, making supplemental testing for other EOs important if contact allergy is suspected; however, testing the patient’s own products is imperative, as there is strong variability in the composition of EOs. Additionally, aged oils may have been exposed to light, oxygen, or varying temperatures, which could result in the formation of additional allergenic chemicals not present in commercially available preparations.¹⁵ In addition to commercially available allergens, we test patient-provided EOs either as is in semi-open fashion (ie, EOs are applied to patient’s back with a cotton swab, allowed to dry, covered with adhesive tape, and read at the same interval as other patch tests²³) or occasionally dilute them to 1% or 10% (in olive oil or mineral oil).

How should I manage a positive patch-test reaction to EOs?

Patients should avoid relevant EO allergens in their products and environment, which can be easily achieved with the use of the American Contact Dermatitis Society’s Contact Allergen Management Program or similar databases.

Final Interpretation

We are ubiquitously exposed to EOs every day—through the products we use at home, at work, and in our environment. Essential oils make their place in the world by providing sweet-smelling aromas in addition to their alleged therapeutic properties; however, beware, EOs may be the culprit of your next patient’s allergic contact dermatitis.

To the Editor:

In 1998, 2-octyl-cyanoacrylate (2-CA) tissue adhesive gained US Food and Drug Administration approval for topical application to easily hold closed approximated skin edges from surgical excisions and simple trauma-induced lacerations.¹ It has since been employed for a number of off-label indications, including sutureless circumcision,² skin graft fixation,³ pericatheter leakage,⁴ and intracorporeal use to control air leaks during lung resection.⁵ Animal investigations additionally have attempted to elucidate potential future uses of 2-CA for procedures such as inguinal hernia repair,⁶ bowel anastomosis,⁷ incisional hernia repair with mesh,⁸ and microvascular anastomosis.⁹ Compared to sutures, 2-CA offers ease and rapidity of application, a water-resistant barrier, and equivalent cosmetic results, as well as eliminates the need for suture removal.¹⁰ As 2-CA is used with increasing frequency across a variety of settings, there arises a greater need to be mindful of the potential complications of its use, such as irritant contact dermatitis (ICD), allergic contact dermatitis (ACD), and cutaneous id reaction.

A 14-year-old adolescent boy with no notable medical history and no known allergies underwent a minimally invasive Nuss procedure¹¹ (performed by P.L.G.) for the repair of severe pectus excavatum. Two 4-cm incisions were made—one in each lateral chest wall at the approximately eighth intercostal space—to facilitate the introduction of the Nuss bar. The surgical wounds were closed with 2 layers of running polyglactin 910 suture before 2-CA was applied topically to the incision sites. The surgery was well tolerated, and the patient’s wounds healed without incident. When the patient was evaluated for Nuss bar removal 3 years later, incision sites were noted to be well healed, and he exhibited no other skin lesions. The original incision sites (bilateral chest walls) were utilized to facilitate surgical Nuss bar removal. The wounds were closed in 4 layers and 2-CA was again applied topically to the incision sites. There were no intraoperative complications; no devices, drains, or tissue implants were left in the patient at the conclusion of the procedure.

One week later, via text message and digital photographs, the patient reported intense pruritus at the bilateral chest wall incision sites, which were now surrounded by symmetric 1-cm erythematous plaques and associated sparse erythematous satellite papules (Figure 1). The patient denied any fevers, pain, swelling, or purulent discharge from the wounds. He was started on hydrocortisone cream 1% twice daily as well as oral diphenhydramine 25 mg at bedtime with initial good effect.

Allergic contact dermatitis is a type IV hypersensitivity reaction that appears after initial sensitization to an allergen followed by re-exposure. Our patient presented with symmetric erythematous plaques at the surgical incision sites 1 week after 2-CA had been applied. During this interval, sensitization to the inciting allergen occurred. The allergen is taken up by antigen-presenting cells, which then migrate to lymph nodes where they encounter naïve T lymphocytes that subsequently undergo clonal expansion to produce a cohort of T cells that are capable of recognizing the allergen. If subsequent exposure to the specific allergen takes place, an elicitation phase occurs in which primed T cells are incited to release mediators of inflammation that engender the manifestations of ACD within 24 to 72 hours.^18,20 Sensitization may be promoted by skin barrier impairments such as dermatitis or a frank wound.^12,20 In most cases, the patient is unaware that sensitization has occurred, though a primary ACD within 5 to 15 days after initial exposure to the inciting allergen rarely may be observed.¹⁸ Although our patient had 2-CA applied to his surgical wounds at 14 years of age, it was unlikely that sensitization took place at that time, as it was 1 week rather than 1 to 3 days before he experienced the cutaneous eruption associated with his second 2-CA exposure at 17 years of age.

Cyanoacrylate tissue adhesive also may cause ICD resulting from histotoxic degradation products such as formaldehyde and cyanoacetate that are capable of compromising cutaneous barrier function. Keratinocytes that have had their membranes disturbed release proinflammatory cytokines, which recruit cells of the innate immune system as well as T lymphocytes to the site of insult to facilitate the inflammatory response. The manifestations of ICD include erythema, edema, and local necrosis that can compromise wound healing.²⁰ The speed at which a given cyanoacrylate adhesive degrades is proportional to the length of its carbon side chain. Those with shorter side chains—ethyl and methyl cyanoacrylate—degrade more rapidly into formaldehyde and cyanoacetate; 2-CA possesses a longer side chain and therefore degrades more slowly, which should, in theory, lessen its potential to cause ICD.²⁰ Because it may take 7 to 14 days before 2-CA will spontaneously peel from the application site, however, its potential to evoke ICD nevertheless exists.

Treatment of ICD entails removing the irritant while concurrently working to restore the skin’s barrier with emollients. Although topical corticosteroids often are reflexively prescribed to treat rashes, some believe that their use should be avoided in cases of ICD, as their inhibitory effects on epidermal lipid synthesis may further impair the skin’s barrier.²¹ For cases of ACD, with or without an accompanying id reaction, topical corticosteroids are the mainstay of therapy. It is customary to start with a higher-potency topical steroid such as clobetasol and taper to lower-potency steroids as the patient’s condition improves. Steroid ointments are petroleum based and are capable of causing 2-CA to separate from the skin.¹⁰ As a result, they should be used with care when being applied to an area where 2-CA is maintaining dermal closure. Systemic corticosteroids may be warranted in cases with involvement of more than 20% of the body surface area and should start to provide relief within 12 to 24 hours.²² Oral antihistamines and cold water compresses can be added to help address pruritus and discomfort in both ACD and ICD.

Instances of contact dermatitis caused by 2-CA are rare, and progression to an id reaction is rarer still. Physicians should be aware of the possibility of encountering a patient that manifests one or both of these complications whenever 2-CA is employed for skin closure. Physicians who employ 2-CA for skin closure should first ask patients about prior cutaneous reactions to cyanoacrylates including 2-CA and other commonly encountered acrylate-containing products including adhesive wound dressings, dental cements and prostheses, superglue, artificial nails, and adhesives for wigs and false eyelashes. Still, many patients who exhibit acrylate-induced contact dermatitis, with or without an associated id reaction, will not attest to a history of adverse reactions; they simply may not recognize acrylate as the inciting agent. Practitioners across a range of specialties outside of dermatology—surgeons, emergency physicians, and primary care providers—should be prepared to both recognize contact dermatitis and id reaction arising from the use of 2-CA and implement a basic treatment plan that will bring the patient relief without compromising wound closure.

To the Editor:

In 1998, 2-octyl-cyanoacrylate (2-CA) tissue adhesive gained US Food and Drug Administration approval for topical application to easily hold closed approximated skin edges from surgical excisions and simple trauma-induced lacerations.¹ It has since been employed for a number of off-label indications, including sutureless circumcision,² skin graft fixation,³ pericatheter leakage,⁴ and intracorporeal use to control air leaks during lung resection.⁵ Animal investigations additionally have attempted to elucidate potential future uses of 2-CA for procedures such as inguinal hernia repair,⁶ bowel anastomosis,⁷ incisional hernia repair with mesh,⁸ and microvascular anastomosis.⁹ Compared to sutures, 2-CA offers ease and rapidity of application, a water-resistant barrier, and equivalent cosmetic results, as well as eliminates the need for suture removal.¹⁰ As 2-CA is used with increasing frequency across a variety of settings, there arises a greater need to be mindful of the potential complications of its use, such as irritant contact dermatitis (ICD), allergic contact dermatitis (ACD), and cutaneous id reaction.

A 14-year-old adolescent boy with no notable medical history and no known allergies underwent a minimally invasive Nuss procedure¹¹ (performed by P.L.G.) for the repair of severe pectus excavatum. Two 4-cm incisions were made—one in each lateral chest wall at the approximately eighth intercostal space—to facilitate the introduction of the Nuss bar. The surgical wounds were closed with 2 layers of running polyglactin 910 suture before 2-CA was applied topically to the incision sites. The surgery was well tolerated, and the patient’s wounds healed without incident. When the patient was evaluated for Nuss bar removal 3 years later, incision sites were noted to be well healed, and he exhibited no other skin lesions. The original incision sites (bilateral chest walls) were utilized to facilitate surgical Nuss bar removal. The wounds were closed in 4 layers and 2-CA was again applied topically to the incision sites. There were no intraoperative complications; no devices, drains, or tissue implants were left in the patient at the conclusion of the procedure.

One week later, via text message and digital photographs, the patient reported intense pruritus at the bilateral chest wall incision sites, which were now surrounded by symmetric 1-cm erythematous plaques and associated sparse erythematous satellite papules (Figure 1). The patient denied any fevers, pain, swelling, or purulent discharge from the wounds. He was started on hydrocortisone cream 1% twice daily as well as oral diphenhydramine 25 mg at bedtime with initial good effect.

Allergic contact dermatitis is a type IV hypersensitivity reaction that appears after initial sensitization to an allergen followed by re-exposure. Our patient presented with symmetric erythematous plaques at the surgical incision sites 1 week after 2-CA had been applied. During this interval, sensitization to the inciting allergen occurred. The allergen is taken up by antigen-presenting cells, which then migrate to lymph nodes where they encounter naïve T lymphocytes that subsequently undergo clonal expansion to produce a cohort of T cells that are capable of recognizing the allergen. If subsequent exposure to the specific allergen takes place, an elicitation phase occurs in which primed T cells are incited to release mediators of inflammation that engender the manifestations of ACD within 24 to 72 hours.^18,20 Sensitization may be promoted by skin barrier impairments such as dermatitis or a frank wound.^12,20 In most cases, the patient is unaware that sensitization has occurred, though a primary ACD within 5 to 15 days after initial exposure to the inciting allergen rarely may be observed.¹⁸ Although our patient had 2-CA applied to his surgical wounds at 14 years of age, it was unlikely that sensitization took place at that time, as it was 1 week rather than 1 to 3 days before he experienced the cutaneous eruption associated with his second 2-CA exposure at 17 years of age.

Cyanoacrylate tissue adhesive also may cause ICD resulting from histotoxic degradation products such as formaldehyde and cyanoacetate that are capable of compromising cutaneous barrier function. Keratinocytes that have had their membranes disturbed release proinflammatory cytokines, which recruit cells of the innate immune system as well as T lymphocytes to the site of insult to facilitate the inflammatory response. The manifestations of ICD include erythema, edema, and local necrosis that can compromise wound healing.²⁰ The speed at which a given cyanoacrylate adhesive degrades is proportional to the length of its carbon side chain. Those with shorter side chains—ethyl and methyl cyanoacrylate—degrade more rapidly into formaldehyde and cyanoacetate; 2-CA possesses a longer side chain and therefore degrades more slowly, which should, in theory, lessen its potential to cause ICD.²⁰ Because it may take 7 to 14 days before 2-CA will spontaneously peel from the application site, however, its potential to evoke ICD nevertheless exists.

Treatment of ICD entails removing the irritant while concurrently working to restore the skin’s barrier with emollients. Although topical corticosteroids often are reflexively prescribed to treat rashes, some believe that their use should be avoided in cases of ICD, as their inhibitory effects on epidermal lipid synthesis may further impair the skin’s barrier.²¹ For cases of ACD, with or without an accompanying id reaction, topical corticosteroids are the mainstay of therapy. It is customary to start with a higher-potency topical steroid such as clobetasol and taper to lower-potency steroids as the patient’s condition improves. Steroid ointments are petroleum based and are capable of causing 2-CA to separate from the skin.¹⁰ As a result, they should be used with care when being applied to an area where 2-CA is maintaining dermal closure. Systemic corticosteroids may be warranted in cases with involvement of more than 20% of the body surface area and should start to provide relief within 12 to 24 hours.²² Oral antihistamines and cold water compresses can be added to help address pruritus and discomfort in both ACD and ICD.

Instances of contact dermatitis caused by 2-CA are rare, and progression to an id reaction is rarer still. Physicians should be aware of the possibility of encountering a patient that manifests one or both of these complications whenever 2-CA is employed for skin closure. Physicians who employ 2-CA for skin closure should first ask patients about prior cutaneous reactions to cyanoacrylates including 2-CA and other commonly encountered acrylate-containing products including adhesive wound dressings, dental cements and prostheses, superglue, artificial nails, and adhesives for wigs and false eyelashes. Still, many patients who exhibit acrylate-induced contact dermatitis, with or without an associated id reaction, will not attest to a history of adverse reactions; they simply may not recognize acrylate as the inciting agent. Practitioners across a range of specialties outside of dermatology—surgeons, emergency physicians, and primary care providers—should be prepared to both recognize contact dermatitis and id reaction arising from the use of 2-CA and implement a basic treatment plan that will bring the patient relief without compromising wound closure.

To the Editor:

In 1998, 2-octyl-cyanoacrylate (2-CA) tissue adhesive gained US Food and Drug Administration approval for topical application to easily hold closed approximated skin edges from surgical excisions and simple trauma-induced lacerations.¹ It has since been employed for a number of off-label indications, including sutureless circumcision,² skin graft fixation,³ pericatheter leakage,⁴ and intracorporeal use to control air leaks during lung resection.⁵ Animal investigations additionally have attempted to elucidate potential future uses of 2-CA for procedures such as inguinal hernia repair,⁶ bowel anastomosis,⁷ incisional hernia repair with mesh,⁸ and microvascular anastomosis.⁹ Compared to sutures, 2-CA offers ease and rapidity of application, a water-resistant barrier, and equivalent cosmetic results, as well as eliminates the need for suture removal.¹⁰ As 2-CA is used with increasing frequency across a variety of settings, there arises a greater need to be mindful of the potential complications of its use, such as irritant contact dermatitis (ICD), allergic contact dermatitis (ACD), and cutaneous id reaction.

A 14-year-old adolescent boy with no notable medical history and no known allergies underwent a minimally invasive Nuss procedure¹¹ (performed by P.L.G.) for the repair of severe pectus excavatum. Two 4-cm incisions were made—one in each lateral chest wall at the approximately eighth intercostal space—to facilitate the introduction of the Nuss bar. The surgical wounds were closed with 2 layers of running polyglactin 910 suture before 2-CA was applied topically to the incision sites. The surgery was well tolerated, and the patient’s wounds healed without incident. When the patient was evaluated for Nuss bar removal 3 years later, incision sites were noted to be well healed, and he exhibited no other skin lesions. The original incision sites (bilateral chest walls) were utilized to facilitate surgical Nuss bar removal. The wounds were closed in 4 layers and 2-CA was again applied topically to the incision sites. There were no intraoperative complications; no devices, drains, or tissue implants were left in the patient at the conclusion of the procedure.

One week later, via text message and digital photographs, the patient reported intense pruritus at the bilateral chest wall incision sites, which were now surrounded by symmetric 1-cm erythematous plaques and associated sparse erythematous satellite papules (Figure 1). The patient denied any fevers, pain, swelling, or purulent discharge from the wounds. He was started on hydrocortisone cream 1% twice daily as well as oral diphenhydramine 25 mg at bedtime with initial good effect.

Allergic contact dermatitis is a type IV hypersensitivity reaction that appears after initial sensitization to an allergen followed by re-exposure. Our patient presented with symmetric erythematous plaques at the surgical incision sites 1 week after 2-CA had been applied. During this interval, sensitization to the inciting allergen occurred. The allergen is taken up by antigen-presenting cells, which then migrate to lymph nodes where they encounter naïve T lymphocytes that subsequently undergo clonal expansion to produce a cohort of T cells that are capable of recognizing the allergen. If subsequent exposure to the specific allergen takes place, an elicitation phase occurs in which primed T cells are incited to release mediators of inflammation that engender the manifestations of ACD within 24 to 72 hours.^18,20 Sensitization may be promoted by skin barrier impairments such as dermatitis or a frank wound.^12,20 In most cases, the patient is unaware that sensitization has occurred, though a primary ACD within 5 to 15 days after initial exposure to the inciting allergen rarely may be observed.¹⁸ Although our patient had 2-CA applied to his surgical wounds at 14 years of age, it was unlikely that sensitization took place at that time, as it was 1 week rather than 1 to 3 days before he experienced the cutaneous eruption associated with his second 2-CA exposure at 17 years of age.

Cyanoacrylate tissue adhesive also may cause ICD resulting from histotoxic degradation products such as formaldehyde and cyanoacetate that are capable of compromising cutaneous barrier function. Keratinocytes that have had their membranes disturbed release proinflammatory cytokines, which recruit cells of the innate immune system as well as T lymphocytes to the site of insult to facilitate the inflammatory response. The manifestations of ICD include erythema, edema, and local necrosis that can compromise wound healing.²⁰ The speed at which a given cyanoacrylate adhesive degrades is proportional to the length of its carbon side chain. Those with shorter side chains—ethyl and methyl cyanoacrylate—degrade more rapidly into formaldehyde and cyanoacetate; 2-CA possesses a longer side chain and therefore degrades more slowly, which should, in theory, lessen its potential to cause ICD.²⁰ Because it may take 7 to 14 days before 2-CA will spontaneously peel from the application site, however, its potential to evoke ICD nevertheless exists.

Treatment of ICD entails removing the irritant while concurrently working to restore the skin’s barrier with emollients. Although topical corticosteroids often are reflexively prescribed to treat rashes, some believe that their use should be avoided in cases of ICD, as their inhibitory effects on epidermal lipid synthesis may further impair the skin’s barrier.²¹ For cases of ACD, with or without an accompanying id reaction, topical corticosteroids are the mainstay of therapy. It is customary to start with a higher-potency topical steroid such as clobetasol and taper to lower-potency steroids as the patient’s condition improves. Steroid ointments are petroleum based and are capable of causing 2-CA to separate from the skin.¹⁰ As a result, they should be used with care when being applied to an area where 2-CA is maintaining dermal closure. Systemic corticosteroids may be warranted in cases with involvement of more than 20% of the body surface area and should start to provide relief within 12 to 24 hours.²² Oral antihistamines and cold water compresses can be added to help address pruritus and discomfort in both ACD and ICD.

Instances of contact dermatitis caused by 2-CA are rare, and progression to an id reaction is rarer still. Physicians should be aware of the possibility of encountering a patient that manifests one or both of these complications whenever 2-CA is employed for skin closure. Physicians who employ 2-CA for skin closure should first ask patients about prior cutaneous reactions to cyanoacrylates including 2-CA and other commonly encountered acrylate-containing products including adhesive wound dressings, dental cements and prostheses, superglue, artificial nails, and adhesives for wigs and false eyelashes. Still, many patients who exhibit acrylate-induced contact dermatitis, with or without an associated id reaction, will not attest to a history of adverse reactions; they simply may not recognize acrylate as the inciting agent. Practitioners across a range of specialties outside of dermatology—surgeons, emergency physicians, and primary care providers—should be prepared to both recognize contact dermatitis and id reaction arising from the use of 2-CA and implement a basic treatment plan that will bring the patient relief without compromising wound closure.

A variety of toys and other play products can cause contact dermatitis in children because of the nature of their ingredients, according to the results of a review of 25 published articles.

Motortion/Getty Images

“In recent years the products have become a reflection of the compounds used frequently in manufacturing, including metals and plastic compounds,” wrote Justine Fenner, MD, and coauthors, from the departments of dermatology and pediatrics at the Icahn School of Medicine at Mount Sinai, New York,

In a study published in Contact Dermatitis, the researchers identified 25 articles describing dermatitis, rash, or eczema associated with a range of toy and play product terms including Nintendo, PlayStation, putty, glue, doll, game, car, bicycle, slime, iPad, and iPhone.

Overall, nickel was the most common allergen. Cases of nickel dermatitis were associated with laptops, videogame controllers, iPads, and cell phones. Cell phones were the most common electronics associated with contact dermatitis, which was observed on the cheek, periauricular area, and hand, as well as the breast in one case of a patient who kept her phone in her bra.

Other sources of metal allergens were identified in toy cars and costume jewelry, the researchers noted.

In addition, temporary tattoos have been associated with contact dermatitis in children, as have homemade “slime” products, which often contain not only borax or other household detergents, but also glue, shaving cream, or coloring.

However, identification of true allergic contact dermatitis from toys “requires both identification of the chemical contents of toys, which are proprietary in nature, and then epicutaneous allergy testing of these ingredients,” the researchers said.

The study findings were limited by several factors including the consideration only of English-language articles and of cases in children, which thus eliminates other potential cases, the researchers noted. However, the results suggest that dermatologists consider toys as a source of contact dermatitis in children, especially if the time to diagnosis is months to years, they said. “Additionally, it may be useful, as it was in several of the above cases, to have the patient bring in his or her favorite toys for the dermatologist to examine and help further understand the etiology of patient’s rash,” they noted. Moreover, “there is an unmet need for corporations to reveal the chemical ingredients of their toys when allergic contact dermatitis is suspected in order to properly evaluate the patient,” they added.

“Contact dermatitis has been underreported in children and constitutes an ongoing concern,” senior author Nanette Silverberg, MD, chief of pediatric dermatology for the Mount Sinai Health System, said in an interview.

“In particular, toy-related allergy is concerning due to the rise in allergen inclusion in common play items,” she commented. The current analysis identified many case reports of allergens that pediatric dermatologists are frequently seeing in their offices, notably metals such as nickel, she pointed out. “The allergen that always stands out ahead of others is nickel,” Dr. Silverberg said. “Nickel allergy affects about 25% of Americans, often starting in early childhood,” she said. “In the European Union, legislation has been passed to reduce nickel release from metals, which has resulted in less sensitization to nickel. We lack such legislation in the United States,” she added. 

Other trending allergens include methylchloroisothiazolinone/methylisothiazolinone, which may be components of glue or other ingredients in some “slime” products, Dr. Silverberg said.

She advised clinicians to consider patch testing when addressing localized or persistent dermatitis in children. “Furthermore, consider toys as potential relevant allergens that should be modified in order to achieve skin improvement,” she said.

“Greater reporting of pediatric allergic contact dermatitis is needed,” Dr. Silverberg emphasized. “Additionally, surveillance and monitoring for trends in allergen exposures in toys and personal care items is required to analyze this ongoing concern of childhood,” she said.

The study received no outside funding. The researchers had no financial conflicts to disclose.

SOURCE: Fenner J et al. Contact Dermatitis. 2020 Feb 22. doi: 10.1111/cod.13500.

A variety of toys and other play products can cause contact dermatitis in children because of the nature of their ingredients, according to the results of a review of 25 published articles.

Motortion/Getty Images

“In recent years the products have become a reflection of the compounds used frequently in manufacturing, including metals and plastic compounds,” wrote Justine Fenner, MD, and coauthors, from the departments of dermatology and pediatrics at the Icahn School of Medicine at Mount Sinai, New York,

In a study published in Contact Dermatitis, the researchers identified 25 articles describing dermatitis, rash, or eczema associated with a range of toy and play product terms including Nintendo, PlayStation, putty, glue, doll, game, car, bicycle, slime, iPad, and iPhone.

Overall, nickel was the most common allergen. Cases of nickel dermatitis were associated with laptops, videogame controllers, iPads, and cell phones. Cell phones were the most common electronics associated with contact dermatitis, which was observed on the cheek, periauricular area, and hand, as well as the breast in one case of a patient who kept her phone in her bra.

Other sources of metal allergens were identified in toy cars and costume jewelry, the researchers noted.

In addition, temporary tattoos have been associated with contact dermatitis in children, as have homemade “slime” products, which often contain not only borax or other household detergents, but also glue, shaving cream, or coloring.

However, identification of true allergic contact dermatitis from toys “requires both identification of the chemical contents of toys, which are proprietary in nature, and then epicutaneous allergy testing of these ingredients,” the researchers said.

The study findings were limited by several factors including the consideration only of English-language articles and of cases in children, which thus eliminates other potential cases, the researchers noted. However, the results suggest that dermatologists consider toys as a source of contact dermatitis in children, especially if the time to diagnosis is months to years, they said. “Additionally, it may be useful, as it was in several of the above cases, to have the patient bring in his or her favorite toys for the dermatologist to examine and help further understand the etiology of patient’s rash,” they noted. Moreover, “there is an unmet need for corporations to reveal the chemical ingredients of their toys when allergic contact dermatitis is suspected in order to properly evaluate the patient,” they added.

“Contact dermatitis has been underreported in children and constitutes an ongoing concern,” senior author Nanette Silverberg, MD, chief of pediatric dermatology for the Mount Sinai Health System, said in an interview.

“In particular, toy-related allergy is concerning due to the rise in allergen inclusion in common play items,” she commented. The current analysis identified many case reports of allergens that pediatric dermatologists are frequently seeing in their offices, notably metals such as nickel, she pointed out. “The allergen that always stands out ahead of others is nickel,” Dr. Silverberg said. “Nickel allergy affects about 25% of Americans, often starting in early childhood,” she said. “In the European Union, legislation has been passed to reduce nickel release from metals, which has resulted in less sensitization to nickel. We lack such legislation in the United States,” she added. 

Other trending allergens include methylchloroisothiazolinone/methylisothiazolinone, which may be components of glue or other ingredients in some “slime” products, Dr. Silverberg said.

She advised clinicians to consider patch testing when addressing localized or persistent dermatitis in children. “Furthermore, consider toys as potential relevant allergens that should be modified in order to achieve skin improvement,” she said.

“Greater reporting of pediatric allergic contact dermatitis is needed,” Dr. Silverberg emphasized. “Additionally, surveillance and monitoring for trends in allergen exposures in toys and personal care items is required to analyze this ongoing concern of childhood,” she said.

The study received no outside funding. The researchers had no financial conflicts to disclose.

SOURCE: Fenner J et al. Contact Dermatitis. 2020 Feb 22. doi: 10.1111/cod.13500.

A variety of toys and other play products can cause contact dermatitis in children because of the nature of their ingredients, according to the results of a review of 25 published articles.

Motortion/Getty Images

“In recent years the products have become a reflection of the compounds used frequently in manufacturing, including metals and plastic compounds,” wrote Justine Fenner, MD, and coauthors, from the departments of dermatology and pediatrics at the Icahn School of Medicine at Mount Sinai, New York,

In a study published in Contact Dermatitis, the researchers identified 25 articles describing dermatitis, rash, or eczema associated with a range of toy and play product terms including Nintendo, PlayStation, putty, glue, doll, game, car, bicycle, slime, iPad, and iPhone.

Overall, nickel was the most common allergen. Cases of nickel dermatitis were associated with laptops, videogame controllers, iPads, and cell phones. Cell phones were the most common electronics associated with contact dermatitis, which was observed on the cheek, periauricular area, and hand, as well as the breast in one case of a patient who kept her phone in her bra.

Other sources of metal allergens were identified in toy cars and costume jewelry, the researchers noted.

In addition, temporary tattoos have been associated with contact dermatitis in children, as have homemade “slime” products, which often contain not only borax or other household detergents, but also glue, shaving cream, or coloring.

However, identification of true allergic contact dermatitis from toys “requires both identification of the chemical contents of toys, which are proprietary in nature, and then epicutaneous allergy testing of these ingredients,” the researchers said.

The study findings were limited by several factors including the consideration only of English-language articles and of cases in children, which thus eliminates other potential cases, the researchers noted. However, the results suggest that dermatologists consider toys as a source of contact dermatitis in children, especially if the time to diagnosis is months to years, they said. “Additionally, it may be useful, as it was in several of the above cases, to have the patient bring in his or her favorite toys for the dermatologist to examine and help further understand the etiology of patient’s rash,” they noted. Moreover, “there is an unmet need for corporations to reveal the chemical ingredients of their toys when allergic contact dermatitis is suspected in order to properly evaluate the patient,” they added.

“Contact dermatitis has been underreported in children and constitutes an ongoing concern,” senior author Nanette Silverberg, MD, chief of pediatric dermatology for the Mount Sinai Health System, said in an interview.

“In particular, toy-related allergy is concerning due to the rise in allergen inclusion in common play items,” she commented. The current analysis identified many case reports of allergens that pediatric dermatologists are frequently seeing in their offices, notably metals such as nickel, she pointed out. “The allergen that always stands out ahead of others is nickel,” Dr. Silverberg said. “Nickel allergy affects about 25% of Americans, often starting in early childhood,” she said. “In the European Union, legislation has been passed to reduce nickel release from metals, which has resulted in less sensitization to nickel. We lack such legislation in the United States,” she added. 

Other trending allergens include methylchloroisothiazolinone/methylisothiazolinone, which may be components of glue or other ingredients in some “slime” products, Dr. Silverberg said.

She advised clinicians to consider patch testing when addressing localized or persistent dermatitis in children. “Furthermore, consider toys as potential relevant allergens that should be modified in order to achieve skin improvement,” she said.

“Greater reporting of pediatric allergic contact dermatitis is needed,” Dr. Silverberg emphasized. “Additionally, surveillance and monitoring for trends in allergen exposures in toys and personal care items is required to analyze this ongoing concern of childhood,” she said.

The study received no outside funding. The researchers had no financial conflicts to disclose.

SOURCE: Fenner J et al. Contact Dermatitis. 2020 Feb 22. doi: 10.1111/cod.13500.

ORLANDO – Do you have pediatric patients with atopic dermatitis (AD) flares despite complying with treatment, or those who have a new rash in an unusual area? Consider patch testing to assess whether they have allergic contact dermatitis.

Jeff Craven/MDedge News

“Of the patients who are sent to me by local pediatric dermatologists, 50% of them are positive” for allergens, said Jonathan H. Zippin, MD, PhD, director of the contact, occupational, and photodermatitis service at Cornell University, New York.

Speaking at the ODAC Dermatology, Aesthetic, and Surgical Conference, Dr. Zippin noted the prevalence of allergen sensitization is between 13% and 25% among children who are asymptomatic, while the prevalence of sensitization to at least one allergen among children with suspected allergic contact dermatitis (ACD) is between 25% and 96%. In 2014, a study from the National American Contact Dermatitis Group (NACDG) showed that of 883 children who were patch tested, 56.7% had at least one relevant positive patch test (RPPT) result.

“The take-home message here is that pediatric contact dermatitis is common, much more common than a lot of people realize,” Dr. Zippin said.

He described three common scenarios to keep in mind: a worsening rash, a new rash, and failure of a rash to improve after the patient avoids all of his or her positive allergens.

When a rash worsens, patch testing is likely to offer answers. In an analysis of 1,142 patients with suspected ACD aged 18 years or younger (mean age, 10.5 years; 64% female) in the Pediatric Contact Dermatitis Registry study database, 65% had at least one positive patch test, and 48% had at least 1 RPPT (Dermatitis 2016; 27[5] 293-302).

But not all patch testing is the same: The study also found that 24% of the RPPT cases would have been missed if assessed with the T.R.U.E. TEST compared with extended patch testing. If a T.R.U.E. TEST fails to explain generalized atopic dermatitis, the patient should be sent for more comprehensive testing where available, Dr. Zippin advised.

Pediatric patients also have unique allergens clinicians should consider. In the same study, children had a number of allergens similar to those of adults as reported in previous studies, such as nickel, cobalt, and neomycin. However, propylene glycol and cocamidopropyl betaine were allergens identified as unique to the pediatric population.

Another study looking at the same group of patients found that compared with children who did not have AD, children with AD had 7.4 times higher odds of having an RPPT to cocamidopropyl betaine, 7.6 times higher odds of having an RPPT to parthenolide, 5.3 times higher odds of having an RPPT to tixocortol pivalate, 4.2 times higher odds of having an RPPT to wool alcohols, and 4 times higher odds of having an RPPT to lanolin (JAMA Dermatology 2017;153[8]:765-70).

All of these are components of topical medicaments used to treat AD, “either components of emollients that we recommend, or components of steroids that we recommend,” Dr. Zippin pointed out.

One of these allergens could be the culprit when a child develops a new rash but there are no new apparent changes in products, exposures, and activities. Lanolin, also called wool grease, is used in many skin care products, for example. Dr. Zippin described the case of a 6-year-old girl with a history of AD, who presented with a new rash on her scalp and behind her ears, not explained by any obvious changes to products, exposures, or activities. Subsequent patch testing determined that the rash was caused by baby shampoo, which contained cocamidopropyl betaine, which is used in hypoallergenic products. The rash resolved after a different shampoo was used.

“Sometimes, we really have to be thinking when the rash is getting worse, is there something they’re being exposed to that might be an allergen?” Dr. Zippin said.

In patients who have avoided all their positive allergens but a rash has not improved, clinicians should consider systemic contact dermatitis (SCD). Patients can develop SCD through different types of exposures, including transepidermal, transmucosal, oral, intravenous, subcutaneous, intramuscular, inhalation, and implantation routes.

SCD also has a variety of presentations, including pompholyx/dyshidrosis/vesicular dermatitis, maculopapular eruption, chronic pruritus, exfoliative erythroderma/toxiderma, chronic urticaria, erythema multiforme and vasculitis, hyperkeratotic papules of the elbows, acute generalized exanthematous pustulosis, and pruritus ani, according to Dr. Zippin.

SCD should be considered when a patient has a positive patch test to an allergen that is known to cause SCD, and does not clear after avoiding cutaneous exposure to the allergen, Dr. Zippin advised.

Patients will most often develop SCD from plants and herbs, Dr. Zippin noted. Chrysanthemums and chamomile tea are common culprits for compositae allergy and can trigger SCD; other causes are Anacardiaceae, Balsam of Peru, and propolis. Metals (nickel, cobalt, gold, and chromium), medications (aminoglycosides, corticosteroids, and ethylenediamine), and other sources (formaldehyde, propylene glycol in frozen foods, gallates, and methylisothiazolinone) can cause SCD as well.

Methylisothiazolinone in particular is a very common sensitizer, Dr. Zippin said. “If you have a patient who is positive to this, it’s almost always the cause of their problem.”

Balsam of Peru is in a number of different foods, and patients who need to follow a diet free of Balsam of Peru should avoid a long list of foods including citrus; bakery goods; Danish pastry; candy; gum; spices such as cinnamon, cloves, vanilla, curry, allspice, anise, and ginger; spicy condiments such as ketchup, chili sauce, barbecue sauce; chili, pizza, and foods with red sauces; tomatoes; pickles; alcohol (wine, beer, gin, vermouth); tea (perfumed or flavored); tobacco; chocolate and ice cream; and soft drinks (cola or spiced soft drinks).

Patients starting a nickel-free diet should avoid soy, peanuts and other nuts, legumes, chocolate, cocoa, oats, fish, and whole wheat flours. Any elimination diet should last for 3 months but should at least be tried for 3-4 weeks, with gradual reintroduction of foods suspected as triggers once per week. Any type I allergies that are discovered or suspected can be referred to an allergist for allergen challenge and desensitization therapy.

For more information, Dr. Zippin recommended the American Contact Dermatitis Society website for more information.

Dr. Zippin reported that he is the founder and holds stock options at CEP Biotech; is on the medical advisory board and receives stock options from YouV Labs., is a paid consultant and performs industry-sponsored research for Pfizer, receives stock options from Regeneron, and is on the medical advisory board for Hoth Therapeutics Inc. He is on the board of directors for the American Contact Dermatitis Society.

ORLANDO – Do you have pediatric patients with atopic dermatitis (AD) flares despite complying with treatment, or those who have a new rash in an unusual area? Consider patch testing to assess whether they have allergic contact dermatitis.

Jeff Craven/MDedge News

“Of the patients who are sent to me by local pediatric dermatologists, 50% of them are positive” for allergens, said Jonathan H. Zippin, MD, PhD, director of the contact, occupational, and photodermatitis service at Cornell University, New York.

Speaking at the ODAC Dermatology, Aesthetic, and Surgical Conference, Dr. Zippin noted the prevalence of allergen sensitization is between 13% and 25% among children who are asymptomatic, while the prevalence of sensitization to at least one allergen among children with suspected allergic contact dermatitis (ACD) is between 25% and 96%. In 2014, a study from the National American Contact Dermatitis Group (NACDG) showed that of 883 children who were patch tested, 56.7% had at least one relevant positive patch test (RPPT) result.

“The take-home message here is that pediatric contact dermatitis is common, much more common than a lot of people realize,” Dr. Zippin said.

He described three common scenarios to keep in mind: a worsening rash, a new rash, and failure of a rash to improve after the patient avoids all of his or her positive allergens.

When a rash worsens, patch testing is likely to offer answers. In an analysis of 1,142 patients with suspected ACD aged 18 years or younger (mean age, 10.5 years; 64% female) in the Pediatric Contact Dermatitis Registry study database, 65% had at least one positive patch test, and 48% had at least 1 RPPT (Dermatitis 2016; 27[5] 293-302).

But not all patch testing is the same: The study also found that 24% of the RPPT cases would have been missed if assessed with the T.R.U.E. TEST compared with extended patch testing. If a T.R.U.E. TEST fails to explain generalized atopic dermatitis, the patient should be sent for more comprehensive testing where available, Dr. Zippin advised.

Pediatric patients also have unique allergens clinicians should consider. In the same study, children had a number of allergens similar to those of adults as reported in previous studies, such as nickel, cobalt, and neomycin. However, propylene glycol and cocamidopropyl betaine were allergens identified as unique to the pediatric population.

Another study looking at the same group of patients found that compared with children who did not have AD, children with AD had 7.4 times higher odds of having an RPPT to cocamidopropyl betaine, 7.6 times higher odds of having an RPPT to parthenolide, 5.3 times higher odds of having an RPPT to tixocortol pivalate, 4.2 times higher odds of having an RPPT to wool alcohols, and 4 times higher odds of having an RPPT to lanolin (JAMA Dermatology 2017;153[8]:765-70).

All of these are components of topical medicaments used to treat AD, “either components of emollients that we recommend, or components of steroids that we recommend,” Dr. Zippin pointed out.

One of these allergens could be the culprit when a child develops a new rash but there are no new apparent changes in products, exposures, and activities. Lanolin, also called wool grease, is used in many skin care products, for example. Dr. Zippin described the case of a 6-year-old girl with a history of AD, who presented with a new rash on her scalp and behind her ears, not explained by any obvious changes to products, exposures, or activities. Subsequent patch testing determined that the rash was caused by baby shampoo, which contained cocamidopropyl betaine, which is used in hypoallergenic products. The rash resolved after a different shampoo was used.

“Sometimes, we really have to be thinking when the rash is getting worse, is there something they’re being exposed to that might be an allergen?” Dr. Zippin said.

In patients who have avoided all their positive allergens but a rash has not improved, clinicians should consider systemic contact dermatitis (SCD). Patients can develop SCD through different types of exposures, including transepidermal, transmucosal, oral, intravenous, subcutaneous, intramuscular, inhalation, and implantation routes.

SCD also has a variety of presentations, including pompholyx/dyshidrosis/vesicular dermatitis, maculopapular eruption, chronic pruritus, exfoliative erythroderma/toxiderma, chronic urticaria, erythema multiforme and vasculitis, hyperkeratotic papules of the elbows, acute generalized exanthematous pustulosis, and pruritus ani, according to Dr. Zippin.

SCD should be considered when a patient has a positive patch test to an allergen that is known to cause SCD, and does not clear after avoiding cutaneous exposure to the allergen, Dr. Zippin advised.

Patients will most often develop SCD from plants and herbs, Dr. Zippin noted. Chrysanthemums and chamomile tea are common culprits for compositae allergy and can trigger SCD; other causes are Anacardiaceae, Balsam of Peru, and propolis. Metals (nickel, cobalt, gold, and chromium), medications (aminoglycosides, corticosteroids, and ethylenediamine), and other sources (formaldehyde, propylene glycol in frozen foods, gallates, and methylisothiazolinone) can cause SCD as well.

Methylisothiazolinone in particular is a very common sensitizer, Dr. Zippin said. “If you have a patient who is positive to this, it’s almost always the cause of their problem.”

Balsam of Peru is in a number of different foods, and patients who need to follow a diet free of Balsam of Peru should avoid a long list of foods including citrus; bakery goods; Danish pastry; candy; gum; spices such as cinnamon, cloves, vanilla, curry, allspice, anise, and ginger; spicy condiments such as ketchup, chili sauce, barbecue sauce; chili, pizza, and foods with red sauces; tomatoes; pickles; alcohol (wine, beer, gin, vermouth); tea (perfumed or flavored); tobacco; chocolate and ice cream; and soft drinks (cola or spiced soft drinks).

Patients starting a nickel-free diet should avoid soy, peanuts and other nuts, legumes, chocolate, cocoa, oats, fish, and whole wheat flours. Any elimination diet should last for 3 months but should at least be tried for 3-4 weeks, with gradual reintroduction of foods suspected as triggers once per week. Any type I allergies that are discovered or suspected can be referred to an allergist for allergen challenge and desensitization therapy.

For more information, Dr. Zippin recommended the American Contact Dermatitis Society website for more information.

Dr. Zippin reported that he is the founder and holds stock options at CEP Biotech; is on the medical advisory board and receives stock options from YouV Labs., is a paid consultant and performs industry-sponsored research for Pfizer, receives stock options from Regeneron, and is on the medical advisory board for Hoth Therapeutics Inc. He is on the board of directors for the American Contact Dermatitis Society.

ORLANDO – Do you have pediatric patients with atopic dermatitis (AD) flares despite complying with treatment, or those who have a new rash in an unusual area? Consider patch testing to assess whether they have allergic contact dermatitis.

Jeff Craven/MDedge News

“Of the patients who are sent to me by local pediatric dermatologists, 50% of them are positive” for allergens, said Jonathan H. Zippin, MD, PhD, director of the contact, occupational, and photodermatitis service at Cornell University, New York.

Speaking at the ODAC Dermatology, Aesthetic, and Surgical Conference, Dr. Zippin noted the prevalence of allergen sensitization is between 13% and 25% among children who are asymptomatic, while the prevalence of sensitization to at least one allergen among children with suspected allergic contact dermatitis (ACD) is between 25% and 96%. In 2014, a study from the National American Contact Dermatitis Group (NACDG) showed that of 883 children who were patch tested, 56.7% had at least one relevant positive patch test (RPPT) result.

“The take-home message here is that pediatric contact dermatitis is common, much more common than a lot of people realize,” Dr. Zippin said.

He described three common scenarios to keep in mind: a worsening rash, a new rash, and failure of a rash to improve after the patient avoids all of his or her positive allergens.

When a rash worsens, patch testing is likely to offer answers. In an analysis of 1,142 patients with suspected ACD aged 18 years or younger (mean age, 10.5 years; 64% female) in the Pediatric Contact Dermatitis Registry study database, 65% had at least one positive patch test, and 48% had at least 1 RPPT (Dermatitis 2016; 27[5] 293-302).

But not all patch testing is the same: The study also found that 24% of the RPPT cases would have been missed if assessed with the T.R.U.E. TEST compared with extended patch testing. If a T.R.U.E. TEST fails to explain generalized atopic dermatitis, the patient should be sent for more comprehensive testing where available, Dr. Zippin advised.

Pediatric patients also have unique allergens clinicians should consider. In the same study, children had a number of allergens similar to those of adults as reported in previous studies, such as nickel, cobalt, and neomycin. However, propylene glycol and cocamidopropyl betaine were allergens identified as unique to the pediatric population.

Another study looking at the same group of patients found that compared with children who did not have AD, children with AD had 7.4 times higher odds of having an RPPT to cocamidopropyl betaine, 7.6 times higher odds of having an RPPT to parthenolide, 5.3 times higher odds of having an RPPT to tixocortol pivalate, 4.2 times higher odds of having an RPPT to wool alcohols, and 4 times higher odds of having an RPPT to lanolin (JAMA Dermatology 2017;153[8]:765-70).

All of these are components of topical medicaments used to treat AD, “either components of emollients that we recommend, or components of steroids that we recommend,” Dr. Zippin pointed out.

One of these allergens could be the culprit when a child develops a new rash but there are no new apparent changes in products, exposures, and activities. Lanolin, also called wool grease, is used in many skin care products, for example. Dr. Zippin described the case of a 6-year-old girl with a history of AD, who presented with a new rash on her scalp and behind her ears, not explained by any obvious changes to products, exposures, or activities. Subsequent patch testing determined that the rash was caused by baby shampoo, which contained cocamidopropyl betaine, which is used in hypoallergenic products. The rash resolved after a different shampoo was used.

“Sometimes, we really have to be thinking when the rash is getting worse, is there something they’re being exposed to that might be an allergen?” Dr. Zippin said.

In patients who have avoided all their positive allergens but a rash has not improved, clinicians should consider systemic contact dermatitis (SCD). Patients can develop SCD through different types of exposures, including transepidermal, transmucosal, oral, intravenous, subcutaneous, intramuscular, inhalation, and implantation routes.

SCD also has a variety of presentations, including pompholyx/dyshidrosis/vesicular dermatitis, maculopapular eruption, chronic pruritus, exfoliative erythroderma/toxiderma, chronic urticaria, erythema multiforme and vasculitis, hyperkeratotic papules of the elbows, acute generalized exanthematous pustulosis, and pruritus ani, according to Dr. Zippin.

SCD should be considered when a patient has a positive patch test to an allergen that is known to cause SCD, and does not clear after avoiding cutaneous exposure to the allergen, Dr. Zippin advised.

Patients will most often develop SCD from plants and herbs, Dr. Zippin noted. Chrysanthemums and chamomile tea are common culprits for compositae allergy and can trigger SCD; other causes are Anacardiaceae, Balsam of Peru, and propolis. Metals (nickel, cobalt, gold, and chromium), medications (aminoglycosides, corticosteroids, and ethylenediamine), and other sources (formaldehyde, propylene glycol in frozen foods, gallates, and methylisothiazolinone) can cause SCD as well.

Methylisothiazolinone in particular is a very common sensitizer, Dr. Zippin said. “If you have a patient who is positive to this, it’s almost always the cause of their problem.”

Balsam of Peru is in a number of different foods, and patients who need to follow a diet free of Balsam of Peru should avoid a long list of foods including citrus; bakery goods; Danish pastry; candy; gum; spices such as cinnamon, cloves, vanilla, curry, allspice, anise, and ginger; spicy condiments such as ketchup, chili sauce, barbecue sauce; chili, pizza, and foods with red sauces; tomatoes; pickles; alcohol (wine, beer, gin, vermouth); tea (perfumed or flavored); tobacco; chocolate and ice cream; and soft drinks (cola or spiced soft drinks).

Patients starting a nickel-free diet should avoid soy, peanuts and other nuts, legumes, chocolate, cocoa, oats, fish, and whole wheat flours. Any elimination diet should last for 3 months but should at least be tried for 3-4 weeks, with gradual reintroduction of foods suspected as triggers once per week. Any type I allergies that are discovered or suspected can be referred to an allergist for allergen challenge and desensitization therapy.

For more information, Dr. Zippin recommended the American Contact Dermatitis Society website for more information.

Dr. Zippin reported that he is the founder and holds stock options at CEP Biotech; is on the medical advisory board and receives stock options from YouV Labs., is a paid consultant and performs industry-sponsored research for Pfizer, receives stock options from Regeneron, and is on the medical advisory board for Hoth Therapeutics Inc. He is on the board of directors for the American Contact Dermatitis Society.

Hypersensitivity to metal implants remains a controversial field in contact dermatitis and patch testing. With positive reactions to nickel hovering around 20% in patch-tested populations,¹ the question remains whether metal-allergic patients can safely receive metal implants. Unfortunately, large controlled studies are lacking, in part due to ethical concerns of knowingly placing a metal implant in a metal-allergic patient. Much of the focus of implant hypersensitivity reactions (IHRs) has been on orthopedic joints including hips, knees, and shoulders, as well as fixed orthopedic implanted materials such as screws and plates. However, there have been reports of IHRs to cardiac devices including defibrillators, pacemakers, and intracardiac devices; dental hardware including implants, crowns, dentures, and braces; and neurologic and gynecologic devices. For the purposes of this review, we will focus on IHRs to orthopedic implants.

Making the Case for IHRs

There are multiple case reports and series documenting likely orthopedic IHRs in the literature^2-5; however, large prospective studies are lacking. Some of the largest series are from Danish registry studies. In 2009, Thyssen et al⁶ reviewed356 patients who had undergone both total hip arthroplasty and patch testing. Metal allergy frequencies were similar between patch-tested registry patients and patch test controls, showing no increase in positive patch tests to metals after receiving implants. Additionally, implant revision rates were comparable between registry patients with and without patch testing. The group concluded that the risk for revision after hip implantation in metal-allergic patients and the risk for development of metal allergy after implantation were both low.⁶ In 2015, Münch et al⁷ compared 327 patients who had undergone both total knee arthroplasty and patch testing and found that prevalence of allergy to nickel, cobalt, and chromium was similar between patients who had undergone revision surgery and those who had not; however, for patients who had 2 or more knee revisions, there was a higher prevalence of postimplant metal allergy. This study also showed that metal allergy identified before implantation did not increase the risk for postimplantation knee revision surgery or implant failure.⁷ These larger studies suggest that although individual cases of IHR exist, it is likely quite rare.

Patients have been found to have increased levels of chromium (serum and urine) and titanium (serum) following total hip arthroplasty.⁸ Additionally, metal wear particles have been identified in postmortem livers and spleens, which was more prevalent in patients with a history of failed hip arthroplasty.⁹ It is difficult to determine the meaning of this data, as the presence of metal ions does not necessarily indicate allergy or IHR. In 2001, Hallab et al¹⁰ pooled data from several implant cohort studies and concluded that in comparison to a baseline metal sensitivity prevalence of approximately 10%, patients with well-functioning implants had a metal sensitivity–weighted average of 25%, and those with poorly functioning implants had a weighted average of 60%. Again, positive patch testing to metals does not necessarily implicate allergy as the cause of implant failure.

Some small studies have shown that patients with evidence of metal hypersensitivity improve with revision. Zondervan et al¹¹ reviewed results of 46 orthopedic revisions following painful total knee arthroplasty. Patients with knee pain and lymphocyte transformation testing (LTT) positive for metals received hypoallergenic revisions, and those with LTT negative for metals received standard revisions. The group who received hypoallergenic revisions had more pain reduction compared to the standard revision group (37.8% reduction in pain vs 27%). However, this study was limited in that the diagnosis of metal allergy was made entirely on results of LTT.¹¹ In 2012, Atanaskova Mesinkovska et al¹² described 41 patients who underwent orthopedic patch testing following implantation for symptoms including pain, dermatitis, pruritus, joint loosening, edema, and impaired wound healing. Fifteen (37%) patients had positive patch test reactions to metals, and 10 (67%) of them had reactions to metals that were present in their implants. Six (60%) of these patients had their implants removed and their symptoms resolved; the remaining 4 continued to experience implant symptoms.¹² These studies support the existence of rare metal-related orthopedic IHRs and support the concept of proceeding with orthopedic implant revision when indicated, safe, and agreed upon by the surgeon and patient. However, as noted in the series by Zondervan et al,¹¹ not every patient with confirmed metal allergy who undergoes revision improves, so an informed conversation between the patient and surgeon is mandatory.

Types of Orthopedic Implants

Orthopedic implanted materials consist of either dynamic (knees, hips) or static (screws, plates) components. Several generations of hip implants have evolved since the 1960s. First-generation implanted hips were metal-on-metal and had high rates of metal release and sensitization. Metal-on-plastic implants may be less likely to release metal but instead release large polyethylene wear particles. Second-generation metal-on-metal implants reportedly have lower wear rates. With these implants, wear particles are generated but are reportedly smaller than first-generation particles.¹³

Allergens in IHRs

Metals
Metals are the most commonly implicated allergens in orthopedic IHRs. Potentially relevant metal alloys include 316L stainless steel, cobalt-chromium-molybdenum steel, Vitallium alloy, titanium alloy, titanium-tantalum-niobium alloy, and Oxinium (Smith & Nephew).^14,15 Each alloy contains several metals, which can include nickel, chromium, cobalt, manganese, molybdenum, iron, titanium, aluminum, vanadium, niobium, tantalum, and zirconium, among others. For example, 316L stainless steel contains iron, nickel, chromium, manganese, molybdenum, nitrogen, carbon, sulfur, silicon, and phosphorus, whereas Oxinium contains only oxidized zirconium and niobium.

Bone Cement
Bone cement also has been reported in cases of orthopedic IHRs and can contain several chemicals, including methyl methacrylate, N,N-dimethyl-p-toluidine, benzoyl peroxide, hydroquinone, and gentamicin.¹⁴ Other potential exposures include adhesives (cyanoacrylates) and topical antibiotics.

Clinical Presentation

Several clinical presentations of orthopedic IHRs have been described. Perhaps the most commonly recognized is a localized cutaneous eczematous eruption, with dermatitis typically overlying the site of the implanted material.^1,2,16 Generalized cutaneous eczematous IHRs also have been reported, including diffuse generalized dermatitis from a stainless steel orthopedic screw⁴ and nummular dermatitis attributed to vanadium in an orthopedic plate.⁵ Urticaria, vasculitis, and bullous cutaneous reactions, as well as extracutaneous complications, also have been reported.^14,15 Pain, edema, joint loosening or failure, and poor wound healing have been reported,¹² but it remains unclear whether these symptoms represent IHR.

Patch Testing for IHR

Several groups have published recommended patch test series for IHR.^12,14,15 Common components of implant patch testing panels include metals, adhesives (acrylates, epoxy resins) and antibiotics. Importantly, obtaining product information from the manufacturer of the suspected implant can guide which allergens to include in patch testing. Implant and metal panels also are available for commercial purchase.

Other Diagnostic Tests

We rarely (almost never) order LTTs in the workup for potential IHRs. This is an in vitro test that includes lymphocytes, metal ions, and the radioactive marker methyl-3H-thymidine. The goal of the test is to evaluate if patient lymphocytes are reactive or responsive to metal ions. A positive LTT suggests that lymphocytes can respond to the presence of metal ions but does not confirm allergy or the presence of IHR.

Typically, skin or tissue biopsies are not required to make a diagnosis of IHR; however, if performed, histopathology suggestive of IHR can support a suspected diagnosis. Typical findings include but are not limited to spongiotic dermatitis. Eosinophils may or may not be present. Metal disc testing has been utilized for orthopedic IHR but is not currently recommended due to low diagnostic yield. Prick testing rarely is used and also is not a primary method for diagnosis of IHR.¹⁷

Preimplantation Patch Testing

Expert opinion guidelines published by the American Contact Dermatitis Society (ACDS) state that routine preimplantation patch testing is not necessary; however, for those patients with a clear history of contact reactions to metal, preimplantation patch testing can be considered.¹⁷

Patch test results can influence the orthopedic surgeon’s choice of implant material. In one study, when preimplantation patch testing showed a positive patch test reaction to metals, the results influenced the surgeon’s decision-making in all cases.¹²

Postimplantation Patch Testing: Diagnostic Criteria for Metal IHR After Implantation

From 2012 to 2013, Schalock and Thyssen¹⁸ surveyed expert attendees at meetings of the European Society of Contact Dermatitis and the ACDS for their opinions on proposed diagnostic criteria for metal IHRs. Based on these results (N=119), the authors stratified 4 major and 5 minor diagnostic criteria, which were defined based on overall responses of meeting attendees. Major criteria included (1) chronic dermatitis beginning weeks to months after metallic implantation, (2) complete recovery after removal of the offending implant, (3) eruption overlying the metal implant, and (4) positive patch test reaction to a metal used in the implant. Minor criteria included (1) histology consistent with allergic contact dermatitis, (2) morphology consistent with dermatitis (ie, erythema, induration, papules, vesicles), (3) positive in vitro test to metals (eg, lymphocyte transformation test), (4) systemic allergic dermatitis reaction, and (5) therapy-resistant dermatitis reaction. The authors did not describe a scoring system for evaluation and confirmation of a diagnosis of IHR. Instead, the criteria should be used as general guidelines when evaluating patients for possible IHRs. From a standpoint of available diagnostic tests for metal IHR, 86.1% of experts agreed that a positive patch test reaction to a metal used in the implant was suggestive of a diagnosis, whereas a positive in vitro test to metals (LTT) was suggestive of a diagnosis for only 32.2% of respondents. This study was designed specifically for metal IHRs and therefore is not necessarily generalizable for nonmetal IHRs.¹⁸

Final Interpretation

We follow the 2016 ACDS guidelines¹⁷ and complete preimplantation patch testing only in the setting of suspected metal allergy and postimplantation patch testing based on the guidelines described by Schalock and Thyssen.¹⁸ However, an extended conversation is warranted prior to patch testing to ensure the patient fully understands the limitations of the test. Although we have both ordered the LTT, interpretation remains murky, and until this test is standardized, routine use is unlikely to benefit the patient. Until we are more reliably able to predict who will develop hypersensitivity to implanted metals, the decision to remove or revise an implant is one that should be made by a multidisciplinary team that includes the surgeon and the patient.

Hypersensitivity to metal implants remains a controversial field in contact dermatitis and patch testing. With positive reactions to nickel hovering around 20% in patch-tested populations,¹ the question remains whether metal-allergic patients can safely receive metal implants. Unfortunately, large controlled studies are lacking, in part due to ethical concerns of knowingly placing a metal implant in a metal-allergic patient. Much of the focus of implant hypersensitivity reactions (IHRs) has been on orthopedic joints including hips, knees, and shoulders, as well as fixed orthopedic implanted materials such as screws and plates. However, there have been reports of IHRs to cardiac devices including defibrillators, pacemakers, and intracardiac devices; dental hardware including implants, crowns, dentures, and braces; and neurologic and gynecologic devices. For the purposes of this review, we will focus on IHRs to orthopedic implants.

Making the Case for IHRs

There are multiple case reports and series documenting likely orthopedic IHRs in the literature^2-5; however, large prospective studies are lacking. Some of the largest series are from Danish registry studies. In 2009, Thyssen et al⁶ reviewed356 patients who had undergone both total hip arthroplasty and patch testing. Metal allergy frequencies were similar between patch-tested registry patients and patch test controls, showing no increase in positive patch tests to metals after receiving implants. Additionally, implant revision rates were comparable between registry patients with and without patch testing. The group concluded that the risk for revision after hip implantation in metal-allergic patients and the risk for development of metal allergy after implantation were both low.⁶ In 2015, Münch et al⁷ compared 327 patients who had undergone both total knee arthroplasty and patch testing and found that prevalence of allergy to nickel, cobalt, and chromium was similar between patients who had undergone revision surgery and those who had not; however, for patients who had 2 or more knee revisions, there was a higher prevalence of postimplant metal allergy. This study also showed that metal allergy identified before implantation did not increase the risk for postimplantation knee revision surgery or implant failure.⁷ These larger studies suggest that although individual cases of IHR exist, it is likely quite rare.

Patients have been found to have increased levels of chromium (serum and urine) and titanium (serum) following total hip arthroplasty.⁸ Additionally, metal wear particles have been identified in postmortem livers and spleens, which was more prevalent in patients with a history of failed hip arthroplasty.⁹ It is difficult to determine the meaning of this data, as the presence of metal ions does not necessarily indicate allergy or IHR. In 2001, Hallab et al¹⁰ pooled data from several implant cohort studies and concluded that in comparison to a baseline metal sensitivity prevalence of approximately 10%, patients with well-functioning implants had a metal sensitivity–weighted average of 25%, and those with poorly functioning implants had a weighted average of 60%. Again, positive patch testing to metals does not necessarily implicate allergy as the cause of implant failure.

Some small studies have shown that patients with evidence of metal hypersensitivity improve with revision. Zondervan et al¹¹ reviewed results of 46 orthopedic revisions following painful total knee arthroplasty. Patients with knee pain and lymphocyte transformation testing (LTT) positive for metals received hypoallergenic revisions, and those with LTT negative for metals received standard revisions. The group who received hypoallergenic revisions had more pain reduction compared to the standard revision group (37.8% reduction in pain vs 27%). However, this study was limited in that the diagnosis of metal allergy was made entirely on results of LTT.¹¹ In 2012, Atanaskova Mesinkovska et al¹² described 41 patients who underwent orthopedic patch testing following implantation for symptoms including pain, dermatitis, pruritus, joint loosening, edema, and impaired wound healing. Fifteen (37%) patients had positive patch test reactions to metals, and 10 (67%) of them had reactions to metals that were present in their implants. Six (60%) of these patients had their implants removed and their symptoms resolved; the remaining 4 continued to experience implant symptoms.¹² These studies support the existence of rare metal-related orthopedic IHRs and support the concept of proceeding with orthopedic implant revision when indicated, safe, and agreed upon by the surgeon and patient. However, as noted in the series by Zondervan et al,¹¹ not every patient with confirmed metal allergy who undergoes revision improves, so an informed conversation between the patient and surgeon is mandatory.

Types of Orthopedic Implants

Orthopedic implanted materials consist of either dynamic (knees, hips) or static (screws, plates) components. Several generations of hip implants have evolved since the 1960s. First-generation implanted hips were metal-on-metal and had high rates of metal release and sensitization. Metal-on-plastic implants may be less likely to release metal but instead release large polyethylene wear particles. Second-generation metal-on-metal implants reportedly have lower wear rates. With these implants, wear particles are generated but are reportedly smaller than first-generation particles.¹³

Allergens in IHRs

Metals
Metals are the most commonly implicated allergens in orthopedic IHRs. Potentially relevant metal alloys include 316L stainless steel, cobalt-chromium-molybdenum steel, Vitallium alloy, titanium alloy, titanium-tantalum-niobium alloy, and Oxinium (Smith & Nephew).^14,15 Each alloy contains several metals, which can include nickel, chromium, cobalt, manganese, molybdenum, iron, titanium, aluminum, vanadium, niobium, tantalum, and zirconium, among others. For example, 316L stainless steel contains iron, nickel, chromium, manganese, molybdenum, nitrogen, carbon, sulfur, silicon, and phosphorus, whereas Oxinium contains only oxidized zirconium and niobium.

Bone Cement
Bone cement also has been reported in cases of orthopedic IHRs and can contain several chemicals, including methyl methacrylate, N,N-dimethyl-p-toluidine, benzoyl peroxide, hydroquinone, and gentamicin.¹⁴ Other potential exposures include adhesives (cyanoacrylates) and topical antibiotics.

Clinical Presentation

Several clinical presentations of orthopedic IHRs have been described. Perhaps the most commonly recognized is a localized cutaneous eczematous eruption, with dermatitis typically overlying the site of the implanted material.^1,2,16 Generalized cutaneous eczematous IHRs also have been reported, including diffuse generalized dermatitis from a stainless steel orthopedic screw⁴ and nummular dermatitis attributed to vanadium in an orthopedic plate.⁵ Urticaria, vasculitis, and bullous cutaneous reactions, as well as extracutaneous complications, also have been reported.^14,15 Pain, edema, joint loosening or failure, and poor wound healing have been reported,¹² but it remains unclear whether these symptoms represent IHR.

Patch Testing for IHR

Several groups have published recommended patch test series for IHR.^12,14,15 Common components of implant patch testing panels include metals, adhesives (acrylates, epoxy resins) and antibiotics. Importantly, obtaining product information from the manufacturer of the suspected implant can guide which allergens to include in patch testing. Implant and metal panels also are available for commercial purchase.

Other Diagnostic Tests

We rarely (almost never) order LTTs in the workup for potential IHRs. This is an in vitro test that includes lymphocytes, metal ions, and the radioactive marker methyl-3H-thymidine. The goal of the test is to evaluate if patient lymphocytes are reactive or responsive to metal ions. A positive LTT suggests that lymphocytes can respond to the presence of metal ions but does not confirm allergy or the presence of IHR.

Typically, skin or tissue biopsies are not required to make a diagnosis of IHR; however, if performed, histopathology suggestive of IHR can support a suspected diagnosis. Typical findings include but are not limited to spongiotic dermatitis. Eosinophils may or may not be present. Metal disc testing has been utilized for orthopedic IHR but is not currently recommended due to low diagnostic yield. Prick testing rarely is used and also is not a primary method for diagnosis of IHR.¹⁷

Preimplantation Patch Testing

Expert opinion guidelines published by the American Contact Dermatitis Society (ACDS) state that routine preimplantation patch testing is not necessary; however, for those patients with a clear history of contact reactions to metal, preimplantation patch testing can be considered.¹⁷

Patch test results can influence the orthopedic surgeon’s choice of implant material. In one study, when preimplantation patch testing showed a positive patch test reaction to metals, the results influenced the surgeon’s decision-making in all cases.¹²

Postimplantation Patch Testing: Diagnostic Criteria for Metal IHR After Implantation

From 2012 to 2013, Schalock and Thyssen¹⁸ surveyed expert attendees at meetings of the European Society of Contact Dermatitis and the ACDS for their opinions on proposed diagnostic criteria for metal IHRs. Based on these results (N=119), the authors stratified 4 major and 5 minor diagnostic criteria, which were defined based on overall responses of meeting attendees. Major criteria included (1) chronic dermatitis beginning weeks to months after metallic implantation, (2) complete recovery after removal of the offending implant, (3) eruption overlying the metal implant, and (4) positive patch test reaction to a metal used in the implant. Minor criteria included (1) histology consistent with allergic contact dermatitis, (2) morphology consistent with dermatitis (ie, erythema, induration, papules, vesicles), (3) positive in vitro test to metals (eg, lymphocyte transformation test), (4) systemic allergic dermatitis reaction, and (5) therapy-resistant dermatitis reaction. The authors did not describe a scoring system for evaluation and confirmation of a diagnosis of IHR. Instead, the criteria should be used as general guidelines when evaluating patients for possible IHRs. From a standpoint of available diagnostic tests for metal IHR, 86.1% of experts agreed that a positive patch test reaction to a metal used in the implant was suggestive of a diagnosis, whereas a positive in vitro test to metals (LTT) was suggestive of a diagnosis for only 32.2% of respondents. This study was designed specifically for metal IHRs and therefore is not necessarily generalizable for nonmetal IHRs.¹⁸

Final Interpretation

We follow the 2016 ACDS guidelines¹⁷ and complete preimplantation patch testing only in the setting of suspected metal allergy and postimplantation patch testing based on the guidelines described by Schalock and Thyssen.¹⁸ However, an extended conversation is warranted prior to patch testing to ensure the patient fully understands the limitations of the test. Although we have both ordered the LTT, interpretation remains murky, and until this test is standardized, routine use is unlikely to benefit the patient. Until we are more reliably able to predict who will develop hypersensitivity to implanted metals, the decision to remove or revise an implant is one that should be made by a multidisciplinary team that includes the surgeon and the patient.

Hypersensitivity to metal implants remains a controversial field in contact dermatitis and patch testing. With positive reactions to nickel hovering around 20% in patch-tested populations,¹ the question remains whether metal-allergic patients can safely receive metal implants. Unfortunately, large controlled studies are lacking, in part due to ethical concerns of knowingly placing a metal implant in a metal-allergic patient. Much of the focus of implant hypersensitivity reactions (IHRs) has been on orthopedic joints including hips, knees, and shoulders, as well as fixed orthopedic implanted materials such as screws and plates. However, there have been reports of IHRs to cardiac devices including defibrillators, pacemakers, and intracardiac devices; dental hardware including implants, crowns, dentures, and braces; and neurologic and gynecologic devices. For the purposes of this review, we will focus on IHRs to orthopedic implants.

Making the Case for IHRs

There are multiple case reports and series documenting likely orthopedic IHRs in the literature^2-5; however, large prospective studies are lacking. Some of the largest series are from Danish registry studies. In 2009, Thyssen et al⁶ reviewed356 patients who had undergone both total hip arthroplasty and patch testing. Metal allergy frequencies were similar between patch-tested registry patients and patch test controls, showing no increase in positive patch tests to metals after receiving implants. Additionally, implant revision rates were comparable between registry patients with and without patch testing. The group concluded that the risk for revision after hip implantation in metal-allergic patients and the risk for development of metal allergy after implantation were both low.⁶ In 2015, Münch et al⁷ compared 327 patients who had undergone both total knee arthroplasty and patch testing and found that prevalence of allergy to nickel, cobalt, and chromium was similar between patients who had undergone revision surgery and those who had not; however, for patients who had 2 or more knee revisions, there was a higher prevalence of postimplant metal allergy. This study also showed that metal allergy identified before implantation did not increase the risk for postimplantation knee revision surgery or implant failure.⁷ These larger studies suggest that although individual cases of IHR exist, it is likely quite rare.

Patients have been found to have increased levels of chromium (serum and urine) and titanium (serum) following total hip arthroplasty.⁸ Additionally, metal wear particles have been identified in postmortem livers and spleens, which was more prevalent in patients with a history of failed hip arthroplasty.⁹ It is difficult to determine the meaning of this data, as the presence of metal ions does not necessarily indicate allergy or IHR. In 2001, Hallab et al¹⁰ pooled data from several implant cohort studies and concluded that in comparison to a baseline metal sensitivity prevalence of approximately 10%, patients with well-functioning implants had a metal sensitivity–weighted average of 25%, and those with poorly functioning implants had a weighted average of 60%. Again, positive patch testing to metals does not necessarily implicate allergy as the cause of implant failure.

Some small studies have shown that patients with evidence of metal hypersensitivity improve with revision. Zondervan et al¹¹ reviewed results of 46 orthopedic revisions following painful total knee arthroplasty. Patients with knee pain and lymphocyte transformation testing (LTT) positive for metals received hypoallergenic revisions, and those with LTT negative for metals received standard revisions. The group who received hypoallergenic revisions had more pain reduction compared to the standard revision group (37.8% reduction in pain vs 27%). However, this study was limited in that the diagnosis of metal allergy was made entirely on results of LTT.¹¹ In 2012, Atanaskova Mesinkovska et al¹² described 41 patients who underwent orthopedic patch testing following implantation for symptoms including pain, dermatitis, pruritus, joint loosening, edema, and impaired wound healing. Fifteen (37%) patients had positive patch test reactions to metals, and 10 (67%) of them had reactions to metals that were present in their implants. Six (60%) of these patients had their implants removed and their symptoms resolved; the remaining 4 continued to experience implant symptoms.¹² These studies support the existence of rare metal-related orthopedic IHRs and support the concept of proceeding with orthopedic implant revision when indicated, safe, and agreed upon by the surgeon and patient. However, as noted in the series by Zondervan et al,¹¹ not every patient with confirmed metal allergy who undergoes revision improves, so an informed conversation between the patient and surgeon is mandatory.

Types of Orthopedic Implants

Orthopedic implanted materials consist of either dynamic (knees, hips) or static (screws, plates) components. Several generations of hip implants have evolved since the 1960s. First-generation implanted hips were metal-on-metal and had high rates of metal release and sensitization. Metal-on-plastic implants may be less likely to release metal but instead release large polyethylene wear particles. Second-generation metal-on-metal implants reportedly have lower wear rates. With these implants, wear particles are generated but are reportedly smaller than first-generation particles.¹³

Allergens in IHRs

Metals
Metals are the most commonly implicated allergens in orthopedic IHRs. Potentially relevant metal alloys include 316L stainless steel, cobalt-chromium-molybdenum steel, Vitallium alloy, titanium alloy, titanium-tantalum-niobium alloy, and Oxinium (Smith & Nephew).^14,15 Each alloy contains several metals, which can include nickel, chromium, cobalt, manganese, molybdenum, iron, titanium, aluminum, vanadium, niobium, tantalum, and zirconium, among others. For example, 316L stainless steel contains iron, nickel, chromium, manganese, molybdenum, nitrogen, carbon, sulfur, silicon, and phosphorus, whereas Oxinium contains only oxidized zirconium and niobium.

Bone Cement
Bone cement also has been reported in cases of orthopedic IHRs and can contain several chemicals, including methyl methacrylate, N,N-dimethyl-p-toluidine, benzoyl peroxide, hydroquinone, and gentamicin.¹⁴ Other potential exposures include adhesives (cyanoacrylates) and topical antibiotics.

Clinical Presentation

Several clinical presentations of orthopedic IHRs have been described. Perhaps the most commonly recognized is a localized cutaneous eczematous eruption, with dermatitis typically overlying the site of the implanted material.^1,2,16 Generalized cutaneous eczematous IHRs also have been reported, including diffuse generalized dermatitis from a stainless steel orthopedic screw⁴ and nummular dermatitis attributed to vanadium in an orthopedic plate.⁵ Urticaria, vasculitis, and bullous cutaneous reactions, as well as extracutaneous complications, also have been reported.^14,15 Pain, edema, joint loosening or failure, and poor wound healing have been reported,¹² but it remains unclear whether these symptoms represent IHR.

Patch Testing for IHR

Several groups have published recommended patch test series for IHR.^12,14,15 Common components of implant patch testing panels include metals, adhesives (acrylates, epoxy resins) and antibiotics. Importantly, obtaining product information from the manufacturer of the suspected implant can guide which allergens to include in patch testing. Implant and metal panels also are available for commercial purchase.

Other Diagnostic Tests

We rarely (almost never) order LTTs in the workup for potential IHRs. This is an in vitro test that includes lymphocytes, metal ions, and the radioactive marker methyl-3H-thymidine. The goal of the test is to evaluate if patient lymphocytes are reactive or responsive to metal ions. A positive LTT suggests that lymphocytes can respond to the presence of metal ions but does not confirm allergy or the presence of IHR.

Typically, skin or tissue biopsies are not required to make a diagnosis of IHR; however, if performed, histopathology suggestive of IHR can support a suspected diagnosis. Typical findings include but are not limited to spongiotic dermatitis. Eosinophils may or may not be present. Metal disc testing has been utilized for orthopedic IHR but is not currently recommended due to low diagnostic yield. Prick testing rarely is used and also is not a primary method for diagnosis of IHR.¹⁷

Preimplantation Patch Testing

Expert opinion guidelines published by the American Contact Dermatitis Society (ACDS) state that routine preimplantation patch testing is not necessary; however, for those patients with a clear history of contact reactions to metal, preimplantation patch testing can be considered.¹⁷

Patch test results can influence the orthopedic surgeon’s choice of implant material. In one study, when preimplantation patch testing showed a positive patch test reaction to metals, the results influenced the surgeon’s decision-making in all cases.¹²

Postimplantation Patch Testing: Diagnostic Criteria for Metal IHR After Implantation

From 2012 to 2013, Schalock and Thyssen¹⁸ surveyed expert attendees at meetings of the European Society of Contact Dermatitis and the ACDS for their opinions on proposed diagnostic criteria for metal IHRs. Based on these results (N=119), the authors stratified 4 major and 5 minor diagnostic criteria, which were defined based on overall responses of meeting attendees. Major criteria included (1) chronic dermatitis beginning weeks to months after metallic implantation, (2) complete recovery after removal of the offending implant, (3) eruption overlying the metal implant, and (4) positive patch test reaction to a metal used in the implant. Minor criteria included (1) histology consistent with allergic contact dermatitis, (2) morphology consistent with dermatitis (ie, erythema, induration, papules, vesicles), (3) positive in vitro test to metals (eg, lymphocyte transformation test), (4) systemic allergic dermatitis reaction, and (5) therapy-resistant dermatitis reaction. The authors did not describe a scoring system for evaluation and confirmation of a diagnosis of IHR. Instead, the criteria should be used as general guidelines when evaluating patients for possible IHRs. From a standpoint of available diagnostic tests for metal IHR, 86.1% of experts agreed that a positive patch test reaction to a metal used in the implant was suggestive of a diagnosis, whereas a positive in vitro test to metals (LTT) was suggestive of a diagnosis for only 32.2% of respondents. This study was designed specifically for metal IHRs and therefore is not necessarily generalizable for nonmetal IHRs.¹⁸

Final Interpretation

We follow the 2016 ACDS guidelines¹⁷ and complete preimplantation patch testing only in the setting of suspected metal allergy and postimplantation patch testing based on the guidelines described by Schalock and Thyssen.¹⁸ However, an extended conversation is warranted prior to patch testing to ensure the patient fully understands the limitations of the test. Although we have both ordered the LTT, interpretation remains murky, and until this test is standardized, routine use is unlikely to benefit the patient. Until we are more reliably able to predict who will develop hypersensitivity to implanted metals, the decision to remove or revise an implant is one that should be made by a multidisciplinary team that includes the surgeon and the patient.

Recalcitrant acne is a common, unwavering problem in dermatology practices nationwide. However, both gram positive and gram negative infections of the skin can go undiagnosed in patients with acne resistant to the armamentarium of oral and topical therapeutics. Although I often use isotretinoin in patients with cystic or recalcitrant acne, I almost always do a culture prior to initiating therapy, and more often than not, have discovered patients have gram negative and gram positive skin infections resistant to antibiotics commonly used to treat acne.

Yulia Lisitsa/iStock/Getty Images Plus

Makeup is one of the most common culprits of recalcitrant acne. In a study by Bashir and Lambert published in the Journal of Applied Microbiology, 70%-90% of makeup products tested – including lipstick, lip gloss, beauty blenders, eyeliners, and mascara – were found to be contaminated with bacteria. Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli were the most common culprits, and the product with the highest contamination rates were beauty blenders (the small sponges used to apply makeup), which also had high rates of fungal contamination.

Expiration dates on cosmetic products are used to indicate the length of time a preservative in a product can control bacterial contamination. They are printed on packaging as an open jar symbol with the 3M, 6M, 9M, and 12M label for the number of months the product can be opened and used. Unfortunately and unknowingly, most consumers use products beyond the expiration date, and the most common offender is mascara.

Gram positive and gram negative skin infections should be ruled out in all cases of recalcitrant acne. A reminder to note on all culture requisitions to grow gram negatives because not all labs will grow gram negatives on a skin swab. Counseling should also be given to those patients who wear makeup, which should include techniques to clean and sanitize makeup applicators including brushes, tools, and towels. Blenders are known to be used “wet” and are not dried when washed.

It is my recommendation that blenders be a one-time-use-only tool and disposed of after EVERY application. Instructions provided in my clinic are to wash all devices and brushes once a week with hot soapy water, and blow dry with a hair dryer immediately afterward. Lipsticks, mascara wands, and lip glosses should be sanitized with alcohol once a month. Finally, all products need to be disposed of after their expiry.

Dr. Talakoub and Dr. Wesley are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. This month’s column is by Dr. Talakoub. Write to them at [email protected]. They had no relevant disclosures.
 

Resource

Basher A, Lambert P. J Appl Microbiol. 2019. doi: 10.1111/jam.14479.

Recalcitrant acne is a common, unwavering problem in dermatology practices nationwide. However, both gram positive and gram negative infections of the skin can go undiagnosed in patients with acne resistant to the armamentarium of oral and topical therapeutics. Although I often use isotretinoin in patients with cystic or recalcitrant acne, I almost always do a culture prior to initiating therapy, and more often than not, have discovered patients have gram negative and gram positive skin infections resistant to antibiotics commonly used to treat acne.

Yulia Lisitsa/iStock/Getty Images Plus

Makeup is one of the most common culprits of recalcitrant acne. In a study by Bashir and Lambert published in the Journal of Applied Microbiology, 70%-90% of makeup products tested – including lipstick, lip gloss, beauty blenders, eyeliners, and mascara – were found to be contaminated with bacteria. Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli were the most common culprits, and the product with the highest contamination rates were beauty blenders (the small sponges used to apply makeup), which also had high rates of fungal contamination.

Expiration dates on cosmetic products are used to indicate the length of time a preservative in a product can control bacterial contamination. They are printed on packaging as an open jar symbol with the 3M, 6M, 9M, and 12M label for the number of months the product can be opened and used. Unfortunately and unknowingly, most consumers use products beyond the expiration date, and the most common offender is mascara.

Gram positive and gram negative skin infections should be ruled out in all cases of recalcitrant acne. A reminder to note on all culture requisitions to grow gram negatives because not all labs will grow gram negatives on a skin swab. Counseling should also be given to those patients who wear makeup, which should include techniques to clean and sanitize makeup applicators including brushes, tools, and towels. Blenders are known to be used “wet” and are not dried when washed.

It is my recommendation that blenders be a one-time-use-only tool and disposed of after EVERY application. Instructions provided in my clinic are to wash all devices and brushes once a week with hot soapy water, and blow dry with a hair dryer immediately afterward. Lipsticks, mascara wands, and lip glosses should be sanitized with alcohol once a month. Finally, all products need to be disposed of after their expiry.

Dr. Talakoub and Dr. Wesley are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. This month’s column is by Dr. Talakoub. Write to them at [email protected]. They had no relevant disclosures.
 

Resource

Basher A, Lambert P. J Appl Microbiol. 2019. doi: 10.1111/jam.14479.

Recalcitrant acne is a common, unwavering problem in dermatology practices nationwide. However, both gram positive and gram negative infections of the skin can go undiagnosed in patients with acne resistant to the armamentarium of oral and topical therapeutics. Although I often use isotretinoin in patients with cystic or recalcitrant acne, I almost always do a culture prior to initiating therapy, and more often than not, have discovered patients have gram negative and gram positive skin infections resistant to antibiotics commonly used to treat acne.

Yulia Lisitsa/iStock/Getty Images Plus

Makeup is one of the most common culprits of recalcitrant acne. In a study by Bashir and Lambert published in the Journal of Applied Microbiology, 70%-90% of makeup products tested – including lipstick, lip gloss, beauty blenders, eyeliners, and mascara – were found to be contaminated with bacteria. Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli were the most common culprits, and the product with the highest contamination rates were beauty blenders (the small sponges used to apply makeup), which also had high rates of fungal contamination.

Expiration dates on cosmetic products are used to indicate the length of time a preservative in a product can control bacterial contamination. They are printed on packaging as an open jar symbol with the 3M, 6M, 9M, and 12M label for the number of months the product can be opened and used. Unfortunately and unknowingly, most consumers use products beyond the expiration date, and the most common offender is mascara.

Gram positive and gram negative skin infections should be ruled out in all cases of recalcitrant acne. A reminder to note on all culture requisitions to grow gram negatives because not all labs will grow gram negatives on a skin swab. Counseling should also be given to those patients who wear makeup, which should include techniques to clean and sanitize makeup applicators including brushes, tools, and towels. Blenders are known to be used “wet” and are not dried when washed.

It is my recommendation that blenders be a one-time-use-only tool and disposed of after EVERY application. Instructions provided in my clinic are to wash all devices and brushes once a week with hot soapy water, and blow dry with a hair dryer immediately afterward. Lipsticks, mascara wands, and lip glosses should be sanitized with alcohol once a month. Finally, all products need to be disposed of after their expiry.

Dr. Talakoub and Dr. Wesley are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. This month’s column is by Dr. Talakoub. Write to them at [email protected]. They had no relevant disclosures.
 

Resource

Basher A, Lambert P. J Appl Microbiol. 2019. doi: 10.1111/jam.14479.

Shiitake Mushroom Dermatitis 

Given the scattered and erythematous 1- to 2-mm macules and patches in a flagellate pattern on the shoulders, back, and neck, the differential diagnosis included shiitake mushroom dermatitis, bleomycin-induced flagellate dermatitis, dermatomyositis flagellate erythema, excoriation disorder, dermatographism, and keratosis lichenoides chronica. On further questioning, the patient indicated that he had consumed raw shiitake mushrooms 3 days before the onset of the rash. Although the clinical variability for all the conditions on the differential is notable, our patient had a history of consuming raw shiitake mushrooms, denied taking any medications, reported no repeated trauma, and had no muscular involvement or systemic symptoms, making shiitake mushroom dermatitis the most likely diagnosis.¹ Skin biopsy and blood tests were deemed unnecessary. Instead, the patient was prescribed triamcinolone cream 0.1%, counseled to avoid raw or undercooked shiitake mushrooms in the future, and told to follow-up if symptoms did not resolve. The patient's symptoms resolved, as expected. 

Nakamura² first described shiitake mushroom dermatitis in 1977. The condition also is known as flagellate mushroom dermatitis or shiitake toxicoderma. It classically manifests in susceptible patients as a pruritic, linear, flagellated dermatitis within 24 to 48 hours after the consumption of raw or undercooked shiitake mushrooms (Lentinula edodes).³ Although the complete pathogenesis remains unclear, research suggests that either a toxic reaction or a type IV hypersensitivity reaction to lentinan causes the eruption. Lentinan is a thermolabile polysaccharide within the mushroom that is believed to increase the production of IL-1 and cause vasodilatation.⁴  

Shiitake mushroom dermatitis is a clinical diagnosis based on the most common findings of a flagellate-pattern dermatitis consisting of pruritic and erythematous papular or urticarial lesions, usually found on the trunk. Laboratory tests, skin biopsies, and allergy tests have been shown to be nonspecific and inconsistent.⁵ 

Shiitake mushroom dermatitis is a self-limiting condition, with the majority of symptoms resolving after one to several weeks.⁵ The mainstay of treatment is aimed at symptomatic management and usually consists of topical corticosteroids and antihistamines.³ More rapid resolution of symptoms has been reported with the use of short-term balneo-psoralen plus UVA therapy.⁶ 

Although a 2017 review of the literature described only 9 published cases of shiitake mushroom dermatitis within the United States as of July 2015, this number may be misleading given the possibility of more variable and subtle presentations misdiagnosed as a nonspecific dermatitis.⁵ Given this information and the fact that shiitake mushrooms continue to be a popular choice in American cuisine, this case reminds health care providers of the clinical manifestations, differential diagnosis, and management of flagellate dermatitis caused by consuming shiitake mushrooms.

Shiitake Mushroom Dermatitis 

Given the scattered and erythematous 1- to 2-mm macules and patches in a flagellate pattern on the shoulders, back, and neck, the differential diagnosis included shiitake mushroom dermatitis, bleomycin-induced flagellate dermatitis, dermatomyositis flagellate erythema, excoriation disorder, dermatographism, and keratosis lichenoides chronica. On further questioning, the patient indicated that he had consumed raw shiitake mushrooms 3 days before the onset of the rash. Although the clinical variability for all the conditions on the differential is notable, our patient had a history of consuming raw shiitake mushrooms, denied taking any medications, reported no repeated trauma, and had no muscular involvement or systemic symptoms, making shiitake mushroom dermatitis the most likely diagnosis.¹ Skin biopsy and blood tests were deemed unnecessary. Instead, the patient was prescribed triamcinolone cream 0.1%, counseled to avoid raw or undercooked shiitake mushrooms in the future, and told to follow-up if symptoms did not resolve. The patient's symptoms resolved, as expected. 

Nakamura² first described shiitake mushroom dermatitis in 1977. The condition also is known as flagellate mushroom dermatitis or shiitake toxicoderma. It classically manifests in susceptible patients as a pruritic, linear, flagellated dermatitis within 24 to 48 hours after the consumption of raw or undercooked shiitake mushrooms (Lentinula edodes).³ Although the complete pathogenesis remains unclear, research suggests that either a toxic reaction or a type IV hypersensitivity reaction to lentinan causes the eruption. Lentinan is a thermolabile polysaccharide within the mushroom that is believed to increase the production of IL-1 and cause vasodilatation.⁴  

Shiitake mushroom dermatitis is a clinical diagnosis based on the most common findings of a flagellate-pattern dermatitis consisting of pruritic and erythematous papular or urticarial lesions, usually found on the trunk. Laboratory tests, skin biopsies, and allergy tests have been shown to be nonspecific and inconsistent.⁵ 

Shiitake mushroom dermatitis is a self-limiting condition, with the majority of symptoms resolving after one to several weeks.⁵ The mainstay of treatment is aimed at symptomatic management and usually consists of topical corticosteroids and antihistamines.³ More rapid resolution of symptoms has been reported with the use of short-term balneo-psoralen plus UVA therapy.⁶ 

Although a 2017 review of the literature described only 9 published cases of shiitake mushroom dermatitis within the United States as of July 2015, this number may be misleading given the possibility of more variable and subtle presentations misdiagnosed as a nonspecific dermatitis.⁵ Given this information and the fact that shiitake mushrooms continue to be a popular choice in American cuisine, this case reminds health care providers of the clinical manifestations, differential diagnosis, and management of flagellate dermatitis caused by consuming shiitake mushrooms.

Shiitake Mushroom Dermatitis 

Given the scattered and erythematous 1- to 2-mm macules and patches in a flagellate pattern on the shoulders, back, and neck, the differential diagnosis included shiitake mushroom dermatitis, bleomycin-induced flagellate dermatitis, dermatomyositis flagellate erythema, excoriation disorder, dermatographism, and keratosis lichenoides chronica. On further questioning, the patient indicated that he had consumed raw shiitake mushrooms 3 days before the onset of the rash. Although the clinical variability for all the conditions on the differential is notable, our patient had a history of consuming raw shiitake mushrooms, denied taking any medications, reported no repeated trauma, and had no muscular involvement or systemic symptoms, making shiitake mushroom dermatitis the most likely diagnosis.¹ Skin biopsy and blood tests were deemed unnecessary. Instead, the patient was prescribed triamcinolone cream 0.1%, counseled to avoid raw or undercooked shiitake mushrooms in the future, and told to follow-up if symptoms did not resolve. The patient's symptoms resolved, as expected. 

Nakamura² first described shiitake mushroom dermatitis in 1977. The condition also is known as flagellate mushroom dermatitis or shiitake toxicoderma. It classically manifests in susceptible patients as a pruritic, linear, flagellated dermatitis within 24 to 48 hours after the consumption of raw or undercooked shiitake mushrooms (Lentinula edodes).³ Although the complete pathogenesis remains unclear, research suggests that either a toxic reaction or a type IV hypersensitivity reaction to lentinan causes the eruption. Lentinan is a thermolabile polysaccharide within the mushroom that is believed to increase the production of IL-1 and cause vasodilatation.⁴  

Shiitake mushroom dermatitis is a clinical diagnosis based on the most common findings of a flagellate-pattern dermatitis consisting of pruritic and erythematous papular or urticarial lesions, usually found on the trunk. Laboratory tests, skin biopsies, and allergy tests have been shown to be nonspecific and inconsistent.⁵ 

Shiitake mushroom dermatitis is a self-limiting condition, with the majority of symptoms resolving after one to several weeks.⁵ The mainstay of treatment is aimed at symptomatic management and usually consists of topical corticosteroids and antihistamines.³ More rapid resolution of symptoms has been reported with the use of short-term balneo-psoralen plus UVA therapy.⁶ 

Although a 2017 review of the literature described only 9 published cases of shiitake mushroom dermatitis within the United States as of July 2015, this number may be misleading given the possibility of more variable and subtle presentations misdiagnosed as a nonspecific dermatitis.⁵ Given this information and the fact that shiitake mushrooms continue to be a popular choice in American cuisine, this case reminds health care providers of the clinical manifestations, differential diagnosis, and management of flagellate dermatitis caused by consuming shiitake mushrooms.