Pemphigus developed on preexisting dermatoses.

A case of pemphigus foliaceus which initially developed at sites of preexisting psoriasis and a case of pemphigus erythematosus that developed on the lesions of photosensitive erythemas are described. Inflammatory dermatoses can be considered to be local factors which facilitate the autoimmune response of pemphigus, which in turn may induce blistering cutaneous lesions in subclinical patients with autoantibodies.