Exogenous ochronosis in the United States.

Two middle-aged black women reported hyperpigmentation of the face after using bleaching creams containing hydroquinone. Both noted initial lightening of facial pigmentation followed by progressive darkening of the areas to which the cream was applied. After biopsy, they were found to have exogenous ochronosis. These are the fifth and sixth cases of exogenous ochronosis reported in the United States. In this article we review the literature and discuss the possible pathogenesis of exogenous ochronosis.