Vulvar lesion mimicking vitiligo: A case report

Post-inflammatory hypopigmentation (PIH) is an acquired partial or total loss of pigment that occurs as a result of cutaneous inflammation. Clinically, post-inflammatory hypopigmentation is recognized by a discoloration of the skin; however, proper diagnosis requires a skin biopsy. Although post-inflammatory hypopigmentation is similar in appearance to vitiligo, histopathological evaluation highlights the key differences in the presence of melanocytes and melanophages. A 28-year-old woman presented with discoloration in the vulvovaginal area. Physical examination was within normal limits; however, a genital exam revealed a large, intensely white discoloration in an hourglass pattern involving the clitoris, labia majora, and perianal area. Pigmentation was observed at the base of the hair follicles, which is not consistent with vitiligo. The patient consented to a skin biopsy, which was performed without complication. The biopsy showed mild chronic vulvitis and pigment incontinence due to post-inflammatory hypopigmentation. The patient was prescribed a high-potency topical steroid and a significant reduction in lesion area was observed at 3-month follow-up. Proper diagnosis via clinical examination and skin biopsy is essential in the treatment of pigment deficiencies. In cases of post-inflammatory hypopigmentation, the initial cause of inflammation must first be identified in order to provide an effective treatment regimen. When facing uncommon dermatological conditions such as post-inflammatory hypopigmentation, proper histopathological diagnosis, course of treatment, and follow-up are important in order to achieve patient satisfaction. •Post-inflammatory hypopigmentation is a rare pigment disorder that mimics vitiligo.•Histological examination shows melanocytes with pigment incontinence and the presence of melanophages.•Topical steroids and photochemotherapy are effective treatments for post-inflammatory hypopigmentation.