Scabies

A young man presented for evaluation of an intensely pruritic rash involving the penis (Figure A) and hands (Figure B). The problem arose about a month after a party where he had anonymous sexual contact with multiple women.

Key point: Any itchy penile rash should immediately suggest scabies. The latter also typically involves the hands, most notably in the interdigital webspaces and on the volar aspect of the wrist. A scraping from one of the penile papules disclosed an adult scabies mite, which confirmed the diagnosis.

Treatment: The patient was treated with 2 doses of oral ivermectin (each dose 200 μg/kg), taken 2 weeks apart.

Note: The CDC now recommends oral ivermectin as equally efficacious as topical permethrin for first-line scabies therapy. Note, however, that ivermectin tablets are often in short supply, and the drug remains off-label when used for scabies management, according to the FDA.