Systemic lupus erythematosus presenting with oral mucosal lesions: easily missed?

Two caucasian patients are described in whom oral mucosal lesions were the first manifestation of systemic lupus erythematosus. In both cases the diag nosis was delayed despite histological examination of oral lesions. Treatme nt with antimalarials and azathioprine was of significant benefit. In the a bsence of cutaneous or systemic features, distinguishing oral lupus erythem atosus from lichen planus and epidermal dysplasia can be difficult, both cl inically and on histology, and requires a high index of suspicion.