[Delusion of parasitosis due to Wegener's granulomatosis].

A delusion of parasitosis can be idiopathic or due to different somatic or psychiatric disorders. We report on a 48-year-old man who suffered from imagined animals in his nose. A somatic cause could not be found so that we diagnosed an idiopathic delusion of parasitosis. Later, Wegener's granulomatosis, a rare form of autoimmune induced vasculitis, was diagnosed. It was treated successfully with immunosuppressiva. The psychotic symptoms which remitted under risperidone did not return after finishing the neuroleptic medication.