Vulvovaginal pellagra and lichen sclerosus complicating carcinoid syndrome

Pellagra is a rare clinical syndrome caused by niacin deficiency, and although most commonly nutritional in origin, may be secondary to carcinoid syndrome.

A premenopausal nulliparous woman with metastatic carcinoid tumor developed isolated vulvovaginal manifestations characterized by well-demarcated symmetrical vulvar erythema, mild scaling, ulcerations, and dyspareunia. Tryptophan levels were low. Treatment with nicotinamide resulted in dramatic improvement; however, after 2 years of effective treatment, she developed lichen sclerosus.

Patients with carcinoid tumor presenting chronic vulvar lesions should be evaluated for pellagra. Subsequent development of lichen sclerosus at the site of vulvar dermatosis may be a feature of the "Koebner phenomenon," which describes appearance of lichen sclerosus in scarred areas or sites prone to friction.