Vitiligo and alopecia areata are two cutaneous diseases believed to be primarily autoimmune in pathogenesis. While the coexistence of the two conditions in the same patient has been well-described, reports of the two disease processes occurring in the same location are rare. We report the case of a 10-year-old male with an unremarkable past medical history who presented with a single localized area of poliosis with depigmented underlying skin on the frontal scalp. The hair in the affected area was relatively decreased in density. A punch biopsy of the depigmented patch demonstrated features consistent with both vitiligo and alopecia areata. The decreased number of large hair follicles and a focal peribulbar lymphocytic infiltrate around an anagen follicle were suggestive of alopecia areata. A panel of melanocyte-specific stains revealed absent melanocytes in the epidermis, consistent with vitiligo. Loss of microphthalmia-associated transcription factor-positive root sheath cells was seen, suggestive of loss of melanocyte stem cells. The combination of clinical and histopathologic findings supports the theory of a common pathogenesis of alopecia areata and vitiligo.
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