Ulnar Neuropathy Caused by Intraneural Cold Abscess due to Leprosy: Case Report

Ulnar neuropathy due to cubital tunnel syndrome is a common presentation in elective orthopaedic clinics with causes usually attributed to idiopathic chronic compression. However, rare diagnoses should be considered. We present a case of chronic insidious ulnar neuropathy in a 52-year-old female with a 2-year history of progressive left hand weakness and decreased sensation. She was born in West Africa and she was noted to be generally fit and healthy. Surgical exploration and decompression of ulnar nerve showed fusiform swelling and caseous material discharged out from small incision in nerve sheath. Leprotic neuropathy was suspected and confirmed by microbiology lab. Pure neurotic leprosy is extremely rare and nerve biopsy is the gold standard for diagnosis. There were 202,256 new leprosy cases registered globally in 2019 according to WHO (World Health Organization) figures, and disease can present decades after exposure. Leprotic neuropathy should be considered in the differential diagnosis of peripheral ulnar neuropathy even in temperate regions to avoid delay in diagnosis and undesirable sequalae.