ABSTRACT
BACKGROUND: Rosacea is a relatively common inflammatory skin disease characterized by central facial erythema that persists for several months or longer. Experimental studies have demonstrated that rosacea compromises the epidermal barrier protection against allergens and irritants, rendering rosacea patients susceptible to contact hypersensitivity and skin irritation. OBJECTIVE: This study aimed to investigate allergic and irritant reactions to topical agents and cosmetics in rosacea patients using patch tests. METHODS: Rosacea signs and subtypes of 40 patients were recorded and subjective symptoms and clinical experiences related to topical agents and cosmetics were assessed using a questionnaire. Patch tests were performed in these patients using the Korean Standard Series (Chemotechnique Diagnostics, Sweden), the TRUE test® (Mekos Laboratories ApS, Denmark), and 26 selected fragrance and 31 cosmetic antigens (TROLAB, Germany). RESULTS: Of 40 patch-tested patients, 26 (65%) showed at least 1 positive reaction and 13 (32.5%) showed 2 or more positive reactions. The most common allergens were nickel (II) sulfate (50%), cobalt chloride (10%), epoxy resin (7.7%), and thimerosal (7.5%). Thirteen patients (32.5%) experienced irritant patch test reactions. There were no significant differences in allergic or irritant positive reactions between mild, moderate, and severe cases of rosacea or between rosacea subtypes. Irritant reactions were more common in fair-skinned participants. CONCLUSION: Different topical medications are used in the treatment of rosacea patients. Exacerbation of rosacea may be caused by a hypersensitivity reaction or irritation induced by the topical agent or by cosmetics.