A total of 507 (M 121, F 386) cases of facial dermatitis were investigated,of whom 308 (M 49, F 259) had eczema confined to the face. The prevalence of positive patch tests was 45% (229/507). among all the patients, the 2 most frequent allergens were nickel (15.2%) and ammoniated mercury (6.1%), with the incidence nickel sensitivity in men (20%) being greater than in women (13.7%) 56% of the nickel-positive cases were caused by metal spectacle frames. Taiwan's high number of spectacle-wearers, its subtropical climate and the characteristic oriental facial structure are possible major contributing factors. Most ammoniated mercury (AM) sensitive cases resulted from cosmetics. Skin-lightening creams are widely used in Taiwan, but their content is poorly controlled. according to consumer reports, 14.9% (48/322) had applied AM containing cosmetics Of all the cosmetics tested for mercury, 2.2% (60/2711) were positive. [ABSTRACT FROM AUTHOR]