Contact sensitization in Chinese patients with hand eczema.

Background: Contact sensitization is an important cause of hand eczema, a common disease that affects both daily and occupational life. Objective: To describe contact allergens in Chinese patients with hand eczema and to analyze the association between allergens and occupational exposure. Methods: Three hundred sixty-six patients with hand eczema underwent patch testing with a modified North American standard series between September 1989 and December 2009. Results: Positive patch-test reactions were observed in 74% of patients. The most frequent allergens were p-phenylenediamine (22.7%), nickel sulfate (21.9%), fragrance mix (19.9%), ammoniated mercury (19.7%), and carba mix (17.8%). Nickel and fragrance allergy in women, and carba mix and chromate allergy in men, showed gender predilection, and 64.2% of patients developed hand eczema from occupational exposure. Positive reactions to p-phenylenediamine in hairdressers and to chromate in metalworkers and construction workers presented higher frequencies (p < .05). Conclusions: p-Phenylenediamine, nickel, fragrance, mercury, and rubber chemicals are common allergens in Chinese patients with hand eczema. Gender and occupation may cause different exposures; thus, allergens may vary.