Leprosy mimicking lupus erythematosus

Leprosy, a contagious and chronic granulomatous disease caused by Mycobacterium leprae, is classically known to have cutaneous and neurologic sequelae. Leprosy usually has a long incubation period and may manifest with a variety of autoimmune phenomena reminiscent of autoimmune diseases, such as systemic lupus erythematosus (SLE) or rheumatoid arthritis. We describe a case of a 40-year-old man presenting with a long history of recurrent skin rashes and hand numbness, initially diagnosed as carpal tunnel syndrome and SLE, who was later proven to have borderline leprosy. This suggests that this underappreciated disease should still be considered in the differential diagnosis of granulomatous skin rashes with rheumatic manifestations, even in nonendemic regions.