Cosmetics are one of the common causes of contact dermatitis and many new cosmetic products are being introduced rapidly into our market.

Our purpose was to investigate the as is patch test result by several factors including age, cosmetic product and atopic diseases, and to compare as is patch result with those of standard and cosmetic patch tests.

The records of 240 patients were reviewed who had been patch tested with their own cosmetics and toiletries with a clinical impression of cosmetic contact dermatitis at the patch clinic of Kangnam St. Mary's Hospital in the period of 1991-1995.

Of the 95 patients who were tested with European standard series 54 (56.8%) showed a positive reaction and nickel sulfate was the most common allergen. Eighteen (38.3%) of the 47 patients tested with a cosmetic series revealed a positive reaction and imidazolidinyl urea and dodecyl gallate were the most common allergens. In as is patch test, 99 (41.3%) of the 240 patients showed a positive reaction to 248 (7.3%) of the 3403 cosmetics. Common cosmetic products showing positive reactions were skin care products (26.2%), face make-ups (19.8%), and hair preparations (16.9%). There was no statistically significant difference in the positive reaction rate between atopy and non-atopy patients. The positive correlation rate of as is test with standard and cosmetic series was relatively low.

Commercial standard patch test series including cosmetic series are not enough to detect causative allergen in cosmetic contact dermatitis. As is patch test should be encouraged to detect new allergens, because many cosmetic ingredients are developed and introduced in market.