A number of pustular skin diseases share clinical, pathogenetic, and epidemiological aspects with plaque-type psoriasis, and their classification as a separate clinical entity or as a subtype of psoriasis remains controversial, which is also reflected in the multitude of their names. They include generalized pustular psoriasis with its subtypes, acrodermatitis continua suppurativa (Hallopeau), acute pustulosis palmopantaris, palmoplantar pustular psoriasis, and pustular variants of a mostly TNF-blocker triggered paradoxical psoriasiform dermatitis. In this article, the epidemiology, clinical picture, pathogenesis, genetics, and therapy of these pustular skin diseases are described.