Pemphigus foliaceus with pustular presentation in a patient with psoriasis.

Pemphigus foliaceus is a chronic autoimmune disease of the skin, clinically characterized by scaly and crusty cutaneous erosions involving the seborrheic areas. The patient can eventually become erythrodermic. There are reports of atypical cases of pemphigus foliaceus with pustules and neutrophils, and clinical differentiation from generalized pustular psoriasis of von Zumbusch is difficult. We report the case of a 55-year-old man with a history of psoriasis vulgaris that has developed pemphigus foliaceus with pustules, triggered by withdrawal of systemic corticosteroids. This is the first report associating this atypical form of pemphigus with psoriasis, suggesting that an overlap with generalized pustular psoriasis can occur.