(BMJ)—A man in his 50s presented with a 6-year hx of an asymptomatic, well defined 12-cm diameter lesion that had been unresponsive to topical terbinafine. The patient had some loss of fine touch sensation and nociception, but peripheral nerves weren't palpable or tender. Acid fast bacilli in skin smears and results from nested PCR and DNA sequencing confirmed the dx. What is it?
borderline tuberculoid leprosy
erythema annulare centrifugum
mycosis fungoides
tinea faciei
You are correct. Borderline tuberculoid leprosy was diagnosed on the basis of clinical and lab findings. Recognizing that these clinical features may be caused by leprosy may enable earlier dx and tx before disability occurs. The erythema improved after a few weeks of multidrug tx for leprosy.

BMJ 2022;379:e071187