Xanthomatosis are rare cutaneous diseases which usually arise in the presence of a genetic or an acquired disorder of lipidic metabolism. Because of the frequent occurrence of atherosclerotic cardiovascular disease and pancreatitis, it is important for the physician to recognize and treat xanthomas and underlying lipoprotein disorder. We report the case of a 32-year-old white male affected with a dissociative psychosis who developed an eruptive xanthomatosis in the presence of hyperlipoproteinemia type V (Frederickson classification). The patient's history was remarkable for hyperphagia, ethylism and important abdominal pains in the last months. Physical examination revealed an obese man with multiple yellowish papules localized on the trunk and extremities. Histopathology demonstrated a phlogistic infiltration with lipidic material (Sudan III and Sudan black positive) in dermis. Laboratory findings showed a high level of serum triglycerides, cholesterol, glucose and uric acid and abnormal liver function tests. It was impossible to provide an appropriate therapy owing to the low compliance of the patient towards specific diet, drugs and hospitalization. In our case a primary lipidic metabolic disorder and other secondary conditions, such as hyperphagia, alcoholism, adult-onset diabetes, are probably implicated in the pathogenesis of the disease. Otherwise the main role in the determinism, severity and evolution of the dermatosis is played by the patient's psychic status.