A case record of the complicated vulvovaginal-gingival syndrome, a rare type of lichen ruber planus with a severe course in a 22-year-old female patient, is presented. Pathognomonic symptoms of the disease are described: erosions of the oral, vulva, and vagina mucous membranes, resorption of the labia minora, stenosis of the vaginal opening, formation of scars, and strictures. Of interest are the age of onset, progression of the disease during therapy with systemic glucocorticosteroids, and cytostatic agents, which were administered sequentially for a year. The importance of staged management of vulvar and vaginal dermatoses by profile specialists is emphasized, including the use of potent topical glucocorticosteroids, which are the drugs of choice, according to modern Russian and worldwide guidelines on the management of vulva diseases. Ineffectiveness of therapy for a year, despite the timely correct diagnosis, led to changes in the external genitalia anatomy with the loss of the labia minora, scarring of the clitoris, and stenosis of the vaginal opening. In addition, this case record demonstrated a combination of vulvovaginal-gingival syndrome with autoimmune thyroiditis, which is comparable to the literature data and confirms the high frequency of association of the syndrome with autoimmune diseases. The therapy of autoimmune disorders is crucial in achieving remission of dermatosis.