Hair Follicle Melanogenesis Reflected in Hair Pigmentation as a Developmental Factor in Alopecia Areata.

The mechanism of alopecia areata (AA) is not well-elucidated, and hair follicle melanogenesis pathways are implicated as possible sources for autoantigens. After a retrospective medical record review at a single tertiary medical center, the hair color of 112 AA patients were identified and compared to a control group of 104 androgenetic alopecia patients. There were no statistically significant differences in the natural hair color prevalence between the 2 groups (p = 0.164), and hair color was not a predictor of the alopecia type. Our results suggest hair pigmentation, determined by the eumelanin-to-pheomelanin ratio, is not a positive risk factor for AA development. We hope that our study will encourage multiple large-scale, collaborative, retrospective medical reviews to determine if our results are reproducible in diverse patient populations.