Lichen planus and primary biliary cirrhosis.

The association of lichen planus and primary biliary cirrhosis in five patients is reported. The coexistence of the two diseases is probably more than coincidental and may be due to the fact that both conditions are based on an alteration of mechanisms. There is great similarity between primary biliary cirrhosis and chronic graft-versus-host disease and a common pathogenesis for the two entities has been postulated. Since lichen planus is one of the most common manifestations of graft-versus-host disease, its association with primary biliary cirrhosis is of significance, although not unexpected.