Delayed onset of bullous pemphigoid after PUVA and sunlight treatment of psoriasis.

The coexistence of bullous pemphigoid and psoriasis has previously been noted. In most patients, the bullous lesions start during PUVA or UVB therapy of psoriasis. We report on a psoriatic patient who developed bullous pemphigoid approximately three to four weeks after discontinuing PUVA treatment, and then three to four weeks after exposure to natural sunlight. Delayed induction of bullous pemphigoid has not been previously reported, and it raises the question of ultraviolet therapy inducing subclinical or latent bullous pemphigoid in psoriatic patients.