[First-episode psychosis as primary manifestation of medical disease: An update].

A huge variety of medical diseases may potentially present with isolated psychotic symptoms, and disease-specific treatment or management is available for a significant part of them. The initial medical work-up of a first-episode psychosis (FEP) is of crucial importance. This literature review aimed to identify medical conditions potentially revealed by FEP, to list the warning signs of secondary psychosis, and to discuss a screening strategy. Underlying organic conditions may be drugs and medications, neurologic diseases, infections, inflammatory and/or autoimmune pathologies, and metabolic disorders whether of hereditary origin. Each patient presenting with a first-episode psychosis should be evaluated with a precise anamnesis, a careful clinical examination, and routine laboratory tests. Brain imaging and tests (depending on the context) should be performed in the presence of atypical clinical features or "red flags", leading to suspect an organic disease.