Allergic contact dermatitis caused by cocamide diethanolamine

Background. Cocamide DEA (CAS no. 68603-42-9) is a non-ionic surfactant frequently used in industrial, household and cosmetic products for its foam-producing and stabilizing properties. Contact allergy has been reported quite rarely in the past, but recently several caseswere published, raising the question of an increase in the frequency of allergic dermatitis caused by this substance. Objectives. To describe cocamide DEA-allergic patients and their characteristics observed in our department. Methods. Medical charts of patients, investigated between 1990 and December 2015, were retrospectively reviewed for cocamide DEA-allergy. Demographic characteristics and patch test results were analyzed. Results. Out of 1767 patients tested, 18 (1%) presented with an allergic reaction to cocamide DEA, all of them at least with hand dermatitis. Twelve patients had (past) occupational exposure to cocamide DEA. Out of the 18 patients, 15 showed (most often) multiple positive reactions and 7 also suffered from atopic dermatitis. Conclusions. Cocamide DEA allergy is relatively rare, despite frequent use, and an increasing trend was not observed. Reactions to cocamidopropyl betaine and cocamide MEA only occurred in some of the subjects tested. Shampoos and liquid hand soaps/cleansers dominated as sources of exposure. All patients presented with an impaired skin barrier due to atopic and/or previous contact dermatitis.