The pustular forms o f psoriasis make up a heterogeneous entity from a clinical point of view. However, the existence of clinically detectable aseptic pustular lesions is common to all these forms. How they are related to plaque psoriasis, also called psoriasis vulgaris, the most frequent form of psoriasis, and the genetic and molecular mechanisms recently updated in some forms, have renewed interest in these pustular forms, resulting in reconsideration of their place within cutaneous and systemic inflammatory diseases.