The authors describe a girl affected by dermatomyositis, with a quick and grave evolution, which required urgent tracheostomy to reduce the dysphagic symptoms. During the observation the patient showed psychotic symptoms. After the revision of literature, in which no such complication has ever been described, the authors propose an etiopathogenetic interpretation for a generalized acute psycho-organic syndrome, supposing a cerebral hypoxic damage, as vasculitic manifestation, probably complicated by symptoms of hysterical conversion, due to the isolation of the patient in the Department of Intensive Therapy and to the severe physical conditions.