Minocycline-induced pigmentation occurring in two sisters.

Two sisters are described who developed facial pigmentation while on minocycline therapy for acne vulgaris. It is suggested that the possible mechanisms for this relatively uncommon complication occurring in these two patients may be due to either a genetically acquired alteration in metabolic handling of minocycline or to the ethinyloestradiol component of Dianette, which they were also receiving as treatment for their acne vulgaris. It is concluded that patients on minocycline should be regularly screened for signs of hyperpigmentation, especially if they are on other drugs which are known to accentuate pigmentation of skin.