Primary cutaneous nocardiosis.

A case of primary cutaneous nocardiosis due to Nocardia asteroides occurring in a steroid-dependent asthmatic with no history of trauma is presented. He had a 5 month history of painful nodules on his right shin and calf. He was initially treated with a 6 week course of oral cephalexin 500 mg four times daily, followed by a 2 week course of minocycline 100 mg twice daily with worsening of the infection. A 12 week course of oral clarithromycin 500 mg twice daily led to complete resolution. A discussion of the problems associated with antimicrobial susceptibility testing and nocardia resistance is presented.