A case of lichen ruber planus in a patient with familial multiple sclerosis.

Multiple sclerosis and lichen ruber planus are clinically and histologically distinct complex disorders of putative autoimmune aetiology that are fairly commonly observed in isolation but rarely found in combination. Only two previous reports have described lichen skin disorders in association with multiple sclerosis. The present report describes the case of a 51-year-old Caucasian woman exhibiting both familial multiple sclerosis and lichen ruber planus. This combination may have occurred by chance or it might imply that these disorders share common mechanisms in their pathogenesis.