[Dermatology: re-defining psoriasis].

Psoriasis has long been regarded to be one entity, comprising both plaque-type and non plaque-type manifestations. Genetic studies now provide evidence that some pustular forms should be classified separately: a mutation in the gene encoding for the interleukin 36 receptor antagonist (IL36Ra) was f6und to be associated with generalized pustular psoriasis (GPP) in several Tunesian families. This finding was subsequently confirmed in different psoriasis cohorts around the world. Additionally, gain-of-function mutations in the gene for CARD 14 were identified. Clinical implications comprise a different approach to treat GPP through blocking interleukin 1beta.