Sensitization to saw palmetto and minoxidil in separate topical extemporaneous treatments for androgenetic alopecia.

We report a 24-year-old woman with androgenetic alopecia who became sensitized to topical minoxidil following use of an extemporaneous preparation of minoxidil 4% with retinoic acid in a propylene glycol base. She subsequently also became sensitized to saw palmetto (Serenoa repens), a topical herbal extract commonly promoted for the treatment of hair loss.