Six cases of primary biliary cirrhosis complicated by psoriasis.

Six cases of primary biliary cirrhosis (PBC) complicated by psoriasis are presented. Three of six patients had psoriasis vulgaris and three had palmoplantar pustulosis. PBC was diagnosed before the onset of psoriasis in three patients and after the onset of psoriasis in the other three patients. Interestingly, all three cases of psoriasis vulgaris were diagnosed after the onset of PBC. We recognized no obvious characteristics specific to PBC complicated by psoriasis except that all cases were in an early stage of PBC. Although the etiologies of psoriasis and PBC remain unknown, the two diseases have many common features as to pathogenesis. We believe that case of PBC-psoriasis overlap hold the key to clarifying the nature of these diseases.