Role of macrophage infiltration in successful repigmentation in a new periphery‐spreading vitiligo lesion in a male Japanese patient

Abstract Vitiligo is an acquired disorder in which depigmented macules result from mostly autoimmune loss of melanocytes. The initiating process in vitiligo has still been uncertain. Here, we report the case of a 19‐year‐old man with undetermined/unclassified vitiligo with a new periphery‐spreading vitiligo lesion on the right dorsal hand after rigorous sun exposure. Histopathological evaluation showed noticeable infiltration of CD 68 + macrophages, moderate infiltration of CD 3 + T cells, little infiltration of CD 8 + T cells and CD 11c + myeloid dendritic cells, HMB 45/ CD 11c double‐positive cells, and M elan‐A/ MART 1 + deposits in the dermis. We surmised that melanocyte‐derived deposits were mostly phagocytosed by CD 68 + macrophages and were faintly phagocytosed by CD 11c + myeloid dendritic cells, referring distribution of CD 68 + mononuclear cells and melanocyte biomarkers. Complete repigmentation was achieved following topical application of hydrocortisone butyrate propionate 0.1% ointment. We summarize that prompt clearance of debris by macrophages would be essential to an excellent prognosis of complete repigmentation.