The incidence of leukotrichia in segmental vitiligo: implication of poor response to medical treatment.

BACKGROUND: In vitiligo, the melanocyte of the hair follicle is one of the major sources for repigmentation. Segmental vitiligo seems to be often associated with white hairs. However, in the case of small vellus hairs, it is often difficult or impossible to detect hair color. Thus, the real incidence of leukotrichia in segmental vitiligo has not been known. MATERIALS AND METHODS: In this study, we investigated the existence of white hairs in the lesional skin of 82 patients with segmental vitiligo. When it was difficult to detect hair color with the naked eye or a magnifier, a digital microscope with 30× magnification was used. RESULTS: Interestingly, all 82 patients showed leukotrichia in segmental vitiligo independent of age and disease duration. Some patients had more than 90% white hairs in the lesional skin, and they showed poor response to medical treatment. CONCLUSIONS: Based on our results, a very high percentage of patients with segmental vitiligo may be associated with leukotrichia. Many white hairs in segmental vitiligo may contribute to the lack of response with medical treatment. The examination of hair color with a digital microscope may be very useful for the prediction of treatment outcome and decision of treatment modalities.