The autoimmune background in lichen planus.

Fifty-four patients with lichen planus (LP) and 54 age- and sex-matched controls were studied. No increase in the incidence of autoimmune disease was found in the patients with LP or their relatives. There was no increase in the frequency of autoantibodies in the LP group and serum immunoglobulin levels were not altered significantly. In the majority of cases, LP is not part of a generalized autoimmune disturbance.