The paper describes the case of a rare autoimmune disease. Chronic ulcerative stomatitis, also called in English CUS (chronic ulcerative stomatitis) was isolated for the first time by Jaremko in 1990. It is characterized by a chronic progression with periods of remission and relapse. This disease occurs in 90% of cases among mature women in the fifth or sixth decade of life. It is characterized by ulcerations and erosions of the mucous membrane of the mouth, most frequently of the tongue and cheek. The patient's general condition is good. The lesions cause pain that hinders speech, food intake, and the use of dentures. In order to perform a diagnosis, clinical and immunopathological examinations are required. In direct immunofluorescence (DIF) of lesion samples, and in indirect immunofluorescence (IIF) of the patients' serum, antinuclear antibodies of IgG called SES-ANA are detected. The treatment of choice for chronic ulcerative stomatitis are antimalarials or antimalarial drugs associated with corticosteroids.

Key words: chronic ulcerative stomatitis, oral cavity, diagnosis, treatment.