This is a case report of lichen planus (LP) with multiple system involvement. A 35-year-old female patient was admitted in November 2014 with a 5-year history of painful/difficult sexual intercourse and loss of oral mucosa, and an 8-year history of focal hair loss. Earlier, the patient had been unable to adhere to corticosteroid therapy because of severe adverse side effects. In September 2014, labia minora mucosa defects and stricture of the urethral orifice (with dysuria), vaginal orifice, and vagina were identified. Biopsy was performed and a diagnosis of erosive LP was made. The patient was treated with an oral immunosuppressant (cyclosporine A) and urethral/vaginal dilatation. Urine flow rate and sex life were improved after 6 months and she discontinued medication. Four years later, the patient reported a good overall treatment efficacy. LP can involve multiple systems and should be considered in patients with dyspareunia. Immunosuppressive agents can achieve a satisfactory effect in patients with contraindication to corticosteroid.