Blastomycosis-like pyoderma: successful treatment with low-dose acitretin.

Blastomycosis-like pyoderma typically presents as verrucous plaque(s) with a purulent discharge through multiple sinuses. Two patients with blastomycosis-like pyoderma developing on significantly sun-damaged skin are presented: an 84-year-old man with multiple painful nodules and plaques, and a 92-year-old woman with a solitary plaque on the left calf. Histopathology showed pseudoepitheliomatous hyperplasia with dermal foci of suppuration. Staphylococcus aureus was isolated from a biopsy specimen in the first patient, whereas the latter patient had Prevotella and Corynebacterium species. Investigations for fungi and mycobacteria yielded negative results. These microbiological findings further supported the clinicopathological diagnosis. Both patients failed to respond to oral doxycycline despite the in vitro susceptibility of the organisms. Treatment with low-dose oral acitretin was successful in both patients after 3-4 months.