Contact dermatitis should be suspected in patients with eczematous dermatitis atypical in location, geometric or symmetric in distribution, or unresponsive to or worsened by common therapies, Dr. Catalina Matiz emphasized.
Allergic contact dermatitis is a complex disorder characterized by a type IV delayed-type hypersensitivity reaction that occurs when a patient’s skin is exposed to a substance easily penetrates the skin barrier.
Dr. Catalina Matiz
Increasingly recognized in the United States, many pediatric patients are becoming sensitized to contact allergens found in personal care products, including skin care products, topical medications, and clothing.
A study published by Hill et al. in 2016 reviewed pediatric patch test studies to determine the top contact allergens in children (Expert Rev Clin Immunol. 2016;12[5]:551-61).
Dr. Matiz presented the top 10 allergens discovered by this group, and offered practical advice for allergen avoidance.
Topping the list in descending order are the following:
- Tixocortol pivalate (a corticosteroid).
- Propylene glycol.
- Methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI).
- Formaldehyde.
- Cocamidopropyl betaine.
- Lanolin.
- Benzalkonium chloride.
- Fragrance and balsam of peru.
- Neomycin.
- Nickel.
Dr. Matiz educated meeting attendees on allergen-containing products and clinical correlations suggestive of allergic sensitization to common allergens. Tixocortol pivilate is a corticosteroid present in Class A corticosteroids including hydrocortisone acetate. She highlighted the cross reactivity between class A and class D2 corticosteroids including hydrocortisone butyrate and valerate.
“Usually topical corticosteroid–contact sensitivity manifests as a failure to improve or worsening of existing dermatitis,” emphasized Dr. Matiz of departments of dermatology and pediatrics at the university.
Propylene glycol, benzalkonium chloride, and neomycin also represent top contact allergens frequently found in topical medications. Similarly, lanolin contact sensitivity often presents as refractory or worsening atopic dermatitis. “Lanolin, also known as wool alcohol, is commonly found in emollients, medications, and personal care products used by atopic dermatitis patients,” Dr. Matiz stressed.
Methylchloroisothiazolinone/methylisothiazolinone represent preservatives commonly found in wet wipes, hypoallergenic, and sensitive skin products. This was the allergen of the year in 2013 and was subsequently removed from many wet wipe formulations and products in response.
In addition to acute management of allergic contact dermatitis with corticosteroids, Dr. Matiz further emphasized the importance of preemptive avoidance of the top ten allergens.
She recommends patch testing if no clinical improvement is evident after 8 weeks of common allergen avoidance, for definitive allergen identification.
Dr. Matiz said she had no relevant financial disclosures.