Leukoderma acquisitum centrifugum (halo nevus) developed following type 1 leprosy reaction

Abstract

A 35-year-old subpolar lepromatous leprosy patient had completed 24 months WHO/MDT/MB, then followed by the 2nd regimen composed of diaphenylsulfone and minocycline (MINO). Ten months later from the 2nd regimen, he developed type 1 leprosy reaction (T1R) having facial nerve paresis. Another 1 month later, several lesions of leukoderma acquisitum centrifugum (halo nevus) were noticed with some other depigmented lesions. On the pathological examination, nevus cell nests were intermingled with foamy macrophages, accompanied with inflammatory lymphocytes. Macrophages were positively stained with mycobacterium leprae specific anti-phenolic glycolipid-I antibody. During T1R, foamy macrophages and coexisted nevus cells should have been severely attacked. The destruction of nevus cells is supposed to trigger the immune response leading to the leukoderma. On the other hand, some components released from injured nerve tissues, that have common antigenicity with melanin-forming cells, also might have participated in the appearance of leukoderma. MINO-related autoimmunity seemed not to be involved in this case, based on the clinical course.