Leprosy with dystrophy in twenty nails: Detection of acid-fast bacilli in nail biopsy

Leprosy is a chronic granulomatous infectious disease caused by Mycobacterium leprae (M. leprae) and/or M. lepromatosis that has a wide spectrum of clinical presentations and multi-organ involvement, primarily on the skin and peripheral nerves. Recent studies have addressed the possibility of nail involvement in leprosy, but to this day limited studies have provided histological evidence confirming the presence of acid-fast bacilli (AFB) in the nail apparatus. A case of lepromatous leprosy-related dystrophy in 20 nails in a 37-year-old male was reported. Physical examination revealed, on all 20 nails, discoloration and damage to the entire nail plate in the form of a thickened and rough surface of nail plates with dense subungual debris. AFB from a slit-skin smear were found. A biopsy of the nail bed, nail matrix, and skin lesion on the left lower leg revealed granulomas composed of foam cells, histiocytes, and lymphocytes. Fite stain was positive and found globi of AFB from the nail bed and matrix, confirming direct effect by AFB. The patient showed clinical improvement following multibacillary multidrug therapy. This case highlights the importance of nail biopsy in diagnosing leprosy-related nail dystrophy and the role of histopathology in confirming bacterial infection.