Discussion: This 17 yo girl has suffered with what appears to be tinea aminatacea for a decade. It appears unlikely that this is psoriasis. Tinea capitis has not been ruled out. I have found KOH preps from the scalp difficult, so did a fungal culture. Her bacterial culture showed 3+ S. aureus but I suspect this is a secondary invader. My plan at this time is to treat with two weeks of an antibiotic based on sensitivities, and start on terbinafine pending fungal culture. If culture negative and if these approaches are not helpful, I may recommend isotretinoin. The use of this has not been reported for T. aminatacea; but it makes some sense. The other question I have is whether a scalp biopsy may be helpful.