Coexistence of psoriasis vulgaris and bullous diseases.

The coexistence of psoriasis vulgaris and bullous diseases has been described in the literature, mainly with bullous pemphigoid. In the majority of cases the bullous eruption has been thought to be related to antipsoriatic treatment. We describe nine cases of psoriasis vulgaris that were associated with bullous diseases: five bullous pemphigoid, one cicatricial pemphigoid, and three pemphigus vulgaris. The association between psoriasis vulgaris and these bullous diseases may be explained on an immunologic basis.