© 2022 MJH Life Sciences and Dermatology Times and Multimedia Medical, LLC. All rights reserved.
© 2022 MJH Life Sciences™ , Dermatology Times and Multimedia Medical, LLC. All rights reserved.
Conference | American Academy of Dermatology
In her presentation at the recent American Academy of Dermatology Annual Meeting, Peggy A. Wu, MD, MPH, discussed the most common causes for systemic contact dermatitis, and how diet may play a significant role.
Systemic contact dermatitis (SCD) is a condition that occurs in contact-sensitized patients either orally, through inhalation, transcutaneously, or intravenously exposed. This can result in a type 4 hypersensitivity reaction, said Peggy A. Wu, MD, MPH, dermatologist at the University of California Davis Dermatology, Sacramento, California.
She discussed the main causes of these reactions and how it connects to a person’s diet in her presentation at the 2022 American Academy of Dermatology (AAD) Annual Meeting, held March 25 to 29, in Boston, Massachusetts.
She highlighted that the top substances that cause SCD include medications, plants, metals, balsam or Peru/fragrances, benzoic acid/benzoates, gallates, propylene glycol, aspartame/formaldehyde, and sorbic acid.
Within the top 10 allergens reported from 2017 to 2018, according to Wu, 4 linked back to preservatives: methylisothiazolinone, methylchloroisothiazolinonem, formaldehyde, and benzisothiazolinone. Additionally, 3 were fragrances (fragrance mix I, hydroperoxides of linalool, and M. pereirae resin/balsam of Peru), 2 metals (nickel sulfate hexahydrate, and cobalt), and 1 hair dye (4-phenylenediamine).
Nickel SCD, Wu explained, can clinically present on the palms and soles as a vesicular rash and pompylox and can also manifest on the bilateral extensor elbows. Irritants may be found in many places like metals can be found in foods. For example, chromium can be found in potatoes, meats, tea, nuts, grapes, nutritional supplements, multivitamins, and dyes. Even cobalt can be found in flaxseeds, chickpeas, chocolate, nuts, and vitamin B12.
Balsam of Peru, which is derived from the resin of the topical tree myroxylon balsamum pereirae in Central and South America, is a marker of fragrance allergy, she said. A balsam of Peru allergy clinical presentation includes perioral, genital, perianal, symmetrical intertriginous, and vesicular hand atopic dermatitis (AD). Benzoic acid or benzoates, a component of balsam of Peru, is an antimicrobial preservative found in personal care products, food, and drinks.
SCD reactions, according to Wu, are more common in people 60 years and older. Additionally, patients with AD are reported to be more allergic to benzoic acid compared to the general population. Benzoic acid is the forty second most common allergen in patients with AD vs seventy ninth for the general populations, she said. The allergen gallates is an antioxidant that has a perioral or chelitis clinical presentation.
Wu highlighted how to talk with patients experiencing SCD. She explained that a physician should ask the patient to avoid topical contact with allergens. Then, if after 2 months there is no significant improvement, try an elimination diet to see if any foods are causing a reaction. Continue diet avoidance for at least 1 month to evaluate skin response.
She concluded her presentation with additional suggestions. “If a rash does not improve with topical avoidance, there may be a significant component of systemic contact dermatitis. Start with a 1-month trial,” she wrote in the presentation. “There are a number of tools, papers, and websites to guide you and your patients through. Be aware of other common allergens (latex, poison ivy/oak/sumac) and associated foods.”
Shi V, Armstrong AW, Friedman AJ, et al. Dietary triggers and modifications of common dermatologic conditions–an evidence-based approach. Presented at: 2022 American Academy Dermatology Association Annual Meeting; March 25-29, 2022; Boston, Massachusetts.