Patch testing in patients with suspected cosmetic dermatitis: A retrospective study

BACKGROUND: Growing use of cosmetics has led to an increase in the incidence of allergic contact dermatitis (ACD) to cosmetics. Patch testing helps to confirm allergy to cosmetics and pinpoint the exact offending allergens. AIMS AND OBJECTIVES: The study aimed to find the frequency of positive patch test reactions in cases with suspected ACD to cosmetics, and the common allergens responsible for it. METHODS: This is a retrospective record-based study of 58 patients, with suspected ACD to cosmetics, who had undergone patch testing with Indian standard series and Indian cosmetic and fragrance series from January 2013 to December 2015. RESULTS: The majority of patients (60.34%) belonged to the age group of 20-40 years. The most common site of involvement was face (94.8%) followed by neck (22.4%). The most commonly implicated cosmetics in history were soaps (53.4%), and face creams (24.1%). The most common allergens detected on patch testing were cetrimide (20.7%) and thimerosal (15.5%) followed by paraphenylenediamine (6.9%), and fragrance mix (5.2). Positive allergic reactions were obtained in 2.12% of the patches. CONCLUSION: Most common cosmetic products implicated for causing ACD were face creams, soaps, and hair dyes. The principal culprit allergens were cetrimide and thimerosal.