A case of rheumatoid arthritis complicated with mucous membrane pemphigoid.

Rheumatoid arthritis (RA) is a disease of unknown aetiology that causes irreversible joint destruction and has been known to present with not only various extra-articular symptoms, but also various autoimmune disorders. Mucous membrane pemphigoid (MMP) is a chronic autoimmune disease characterised by inflamed and eroded mucosa. The prognosis of MMP can be poor, so early diagnosis and prompt initiation of therapy are necessary for optimal management.