Epidemiology of contact allergy in Singapore.

The prevalence of contact allergy in 2471 patients patch tested in Singapore was 49.2% (571/1160) in women and 49.8% (653/1311) in men (sex difference not significant). The rate appeared to increase with age (43.7% in those less than 20 years, 50.6% between 20 and 49 years, and 63.1% in those greater than 49 years). There was no significant difference in the prevalence of contact allergy among the major races (Chinese, Malay, and Indian) of Singapore. Contact allergies in 16.8% (96/571) of women and 38.9% (254/653) of men (p less than 0.001) were occupational. Nickel, fragrance mix, proflavine, and chromate were common sensitizers. The male:female prevalence of nickel allergy was 1:2 (sex difference p less than 0.001) and for chromate was 7:1 (sex difference p less than 0.001). Chromate sensitivity was occupational in 87.7% (121/138) of men and 47.1% (8/17) of women (sex difference p less than 0.001). Proflavine, neomycin, and clioquinol were the more common medicament sensitizers.