Patch Test Reactions Associated with Food Sources: A Retrospective Analysis of the North American Contact Dermatitis...

Background: Contact dermatitis due to food exposure is underrecognized.Objectives: To characterize relevant allergens associated with food sources and analyze patient and clinical characteristics associated with food-related allergen exposure in patients with a currently relevant positive patch test reaction (PPTR).Methods: We retrospectively analyzed North American Contact Dermatitis Group data from 2001 to 2018, identifying relevant allergens linked to food sources. Patients with currently relevant PPTRs were divided into food-related and non-food-related exposure groups for comparison.Results: Among 43,722 patients, 867 (2.0%) had at least one currently relevant food-related PPTR, accounting for 936 PPTR reactions. The most common allergens were nickel (411, 43.9%), Balsam of Peru (BOP, 287, 30.7%), and fragrance mix 1 (FM1, 60, 6.4%). Carvone (24/139 [17.3%]) and sodium metabisulfite (10/87 [11.5%]) showed the highest food-related proportions. Among 867 food-related patients, the most commonly affected areas were generalized (30.22%) and the hand (19.26%). Patients having food-related PPTR were significantly less likely to involve the hand (OR, 0.59; P < 0.0001) and face (OR, 0.43; P < 0.0001) as compared with nonfood-related patients. Food exposure was associated with a higher likelihood of anogenital dermatitis (P ≤ 0.01 for nickel sulfate, BOP or FM1).Conclusion: Nickel, BOP, and FM1 were the most common food-related allergens. Common sites of dermatitis in patients with food-related PPTR were generalized, anogenital areas, and hands, although involvement of the hands and face was significantly less likely compared with nonfood-related cases.