OBJECTIVE To describe the nature and the frequency of systemic diseases responsible for the pruritus sine materia. Value of this sign as a marker of malignancy. METHODS Prospective study undertaken over five years (1996-2001). METHODS generalized aspect of the pruritus and absence of specific primitive cutaneous lesions of an itching dermatosis. Parameters taken from the data of the anamnesis and the physical examination. Standard biologic and morphologic investigations were done. RESULTS Ninety-five patients included (54 men, 41 women) of 55.5 years average age +/-18.1. In 24 patients, traditional hospitalisation with one average duration of eight days stay +/-3.15 was necessary. In 38 cases (40%), a systemic cause was found. The main conditions were: toxocariasis (8 cases), hematologic diseases (7 cases), chronic renal failure (6 cases), hypothyroidism (5 cases) and iron deficiency (5 cases). A neoplasm was found in eight cases (8,42%): seven hematologic malignancy (3 myeloma, 2 Hodgkin's diseases, 2 myeloproliferative syndromes) and one solid cancer (pulmonary adenocarcinoma). CONCLUSIONS A systemic aetiology was observed in 38 cases (40%). The toxocariasis an underestimated disease comes at the first place. The pruritus sine materia can hide an hematologic malignancy.