Dermoscopy in the diagnosis of tinea nigra plantaris

Tinea nigra is a relatively uncommon dermatiaceous fungal infection, usually caused by Phaeoannellomyces werneckii, that may mimic a melanocytic lesion. We describe the value of epiluminescent dermoscopy of tinea nigra plantaris compared with other common diagnostic tools and procedures available (clinical appearance, potassium hydroxide [KOH], culture, culture mount preparation, and biopsy). A case of tinea nigra plantaris was evaluated clinically, microscopically with KOH, and dermatoscopically. Dermatoscopic findings were evaluated according to the Stolz system. Dermoscopy, clinical presentation, and microscopy with KOH all confirmed the diagnosis, with dermoscopy being the fastest and simplest procedure. Dermoscopy is a useful clinical adjuntive tool in differentiating tinea nigra from a melanocytic lesion.