A Case of Contact Allergic Dermatitis to Topical Minoxidil

Coincidental findings of hypertrichosis in patients on minoxidil led to the development of a topical minoxidil formulation which has been approved by the Food and Drug Administration for the treatment of female pattern hair loss, the most common cause for hair loss in women. The most common side effect of topical minoxidil is irritant contact dermatitis with the typical symptoms of itching and scaling. Most commonly, these symptoms are a result of an allergic reaction to propylene glycol, or less commonly, to minoxidil itself. We present a case of a 27-year-old woman who developed facial swelling following allergic contact dermatitis to minoxidil 5% foam.