Bleaching creams containing hydroquinone are modestly effective in treating some cutane ous pigmentary disorders. Hydroquinone creams frequently cause mild irritant reactions and postinflammatory hyperpigmentation, but rarely allergic reactions. A case of allergic contact dermatitis due to hydroquinone in a 21-year-old woman was confirmed by the patch test. (Kor J Dermatol 1992; 30(3): 381-384)