Pustular Allergic Contact Dermatitis from Topical Minoxidil 5%
TLDR A man had an allergic reaction to minoxidil, which stopped after he discontinued use and started corticosteroids.
A 22-year-old man developed pruriginous papular and pustular lesions on his scalp and forehead after using a 5% minoxidil solution for androgenetic alopecia. The lesions cleared completely after discontinuing minoxidil and starting topical corticosteroid therapy. Patch testing confirmed pustular allergic contact dermatitis to minoxidil. This case highlighted an uncommon reaction to a frequently used dermatological drug, emphasizing the need for patch testing with minoxidil in propylene glycol to identify the allergen. Sensitization to minoxidil is rare but precludes further treatment with the drug.