Melanocytorrhagy and apoptosis in vitiligo: Connecting jigsaw pieces

Vitiligo is an acquired depigmenting disorder characterized by a chronic and progressive loss of melanocytes from the epidermis and follicular reservoir. The mechanism of melanocyte disappearance has never been clearly understood. This review discussed the data supporting the theory of melanocytorrhagy and apoptosis as one of the primary defects underlying melanocyte loss. Theory of melanocytorrhagy proposes that non-segmental vitiligo is a primary melanocytorrhagic disorder with altered melanocyte responses to friction and possibly other types of stress, inducing their detachment and subsequent transepidermal loss. Melanocytes detachment induces apoptosis whereas adherence to basement membrane suppresses apoptosis. The study of apoptosis, mechanisms of its induction, and the ways to block apoptosis is one possible way to find both the causes of depigmentation and medications to prevent its progression.