Segmental vitiligo (SV) is a variant of vitiligo characterized by its early onset and rapid stabilization. The time-limited progression period is 6 to 24 months, while non-segmental vitiligo (NSV) is chronic, possibly with an uncertain lifelong course.
The clinical picture is usually unilateral. Bilaterality has rarely been described. Observational studies on the distribution pattern indicate that the originally stated dermatomal classification is a misinterpretation and classify the distribution pattern as a cutaneous mosaic. In contrast to NSC, the melanocytes of the hair follicles are affected early in SV, so that up to 50 % of patients with segmental vitiligo show poliosis in the lesional areas. The prevalence of concomitant autoimmune diseases (e.g. thyroiditis) is lower in segmental vitiligo (SV) than in non-segmental vitiligo (NSV).