Segmental Vitiligo: Rapid Spread From a Halo Nevus

Vitiligo, a skin condition characterized by depigmentation, is classified into segmental and non-segmental forms based on onset and distribution. While halo nevi typically accompany non-segmental vitiligo, this report documents a rare case where a halo nevus transitioned into segmental vitiligo in an adolescent male. The depigmentation exhibited a distinct unilateral pattern, halting at the midline, which is characteristic of segmental vitiligo. Unlike non-segmental vitiligo, segmental vitiligo is less commonly associated with autoimmune diseases, and this patient's lack of autoimmune comorbidity aligns with that pattern. The depigmentation followed Blaschko's lines, which typically do not cross the midline. Based on the consultation at the time, no immediate treatment was recommended. Recent guidelines suggest first-line use of topical calcineurin inhibitors like tacrolimus or JAK/STAT inhibitors like ruxolitinib. Understanding diverse vitiligo presentations is crucial for more precise diagnosis and treatment strategies.