Idiopathic syndrome of inappropriate secretion of antidiuretic hormone

The authors report a case of idiopathic, chronic inappropriate secretion of antidiuretic hormone (S I A D H) in a 31 months old boy. This inappropriate secretion of ADH was demonstrated by three water tolerance tests and by the bioassays of ADH in urine. These findings were detected five months later suggesting chronic S I A D H. After a review of the literature the mechanism and the treatment of this disease are discussed.