The age of patients with thyrotoxicosis factitia in Italy from 1973 to 1996

Thyrotoxicosis factitia, a syndrome due to the surreptitious ingestion of e xcess thyroid hormones, has generally been diagnosed in young or middle-age d women with psychopathological disturbances. We reviewed all the cases see n at our Institution over a 24-yr period, from 1973 to 1996. All 25 patient s were women. Analysis was restricted to 17 patients who were born and live d in Tuscany (our region), since only these patients were distributed durin g the whole observation period. Diagnosis of thyrotoxicosis factitia was ba sed on the following parameters: elevated serum total and/or free thyroid h ormone levels, undetectable serum thyrotropin levels, low/undetectable seru m thyroglobulin concentration, normal urinary iodine excretion, low/suppres sed thyroidal radioactive iodine uptake (RAIU), absence of goiter, absence of circulating anti-thyroid antibodies. Surreptitious ingestion of thyroid hormone pill was eventually admitted by all patients. Age at diagnosis was >50 yr in 7/17 patients (41 %): 6 of them were distributed in the period 19 95-1996, and one in 1988. Patients older than 60 yr were 5/17 (29%), all in the last two years of the period under investigation. There was an increas e in the age of patients with thyrotoxicosis factitia (p=0.02), which lost a statistical significance when the patients of the 1995-1996 period were e xcluded from analysis (p=0.88). This study provides evidence of an increase d age of patients with thyrotoxicosis factitia in more recent years. From a practical standpoint, our study suggests that thyrotoxicosis factitia shou ld be suspected and adequately looked for even in old patients with thyroto xicosis of inexplicable origin, especially in the absence of goiter and thy roid autoimmune phenomena, and when common causes of low-RAIU hyperthyroidi sm, such as a load with iodine-containing drugs or subacute thyroiditis, ha ve been excluded. (C) 1999, Editrice Kurtis.