Borderline lepromatous leprosy presenting as a single cutaneous plaque

A 38-year-old Indonesian man presented with a single anaesthetic plaque on his right forearm and no other sensory changes. His clinical presentation was consistent with tuberculoid leprosy, but histopathology of a skin biopsy from the lesion showed borderline lepromatous disease. The patient was treated with multidrug therapy for multibacillary disease. Seven months after initiation of treatment his solitary skin anaesthetic plaque became tumid, and he developed multiple small plaques on his arms, legs and face, without evident neuritis. He was clearly in a reversal reaction (type 1), which slowly resolved with treatment of prednisone.