Premium
TRIIODOTHYRONINE THYROTOXICOSIS
Author(s) -
CARTER J. N.,
EASTMAN C. J.,
CASEY J. H.,
FARRELL J. C.,
LAZARUS L.
Publication year - 1975
Publication title -
medical journal of australia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 131
eISSN - 1326-5377
pISSN - 0025-729X
DOI - 10.5694/j.1326-5377.1975.tb111344.x
Subject(s) - medicine , triiodothyronine , incidence (geometry) , thyroidectomy , thyroid , pediatrics , antithyroid drugs , thyroid function tests , radioactive iodine , thyroid function , gastroenterology , graves' disease , physics , optics
The case histories of three patients with triiodothyronine (T3) toxicosis are presented, together with the results of relevant laboratory investigations illustrating the value of serum T3 determinations in the investigation and management of patients with hyperthyroidism. Case reports from 131 other patients with T3 toxicosis have been reviewed, and the clinical features have been compared with those of conventional thyrotoxicosis. Females are affected more frequently than males, but not as commonly as in conventional thyrotoxicosis (approximately 4: 1 compared with 7: 1). The clinical manifestations are similar in the two forms of hyperthyroidism, but in general T3 toxicosis represents a milder form. The mean age of patients with T3 toxicosis is higher than for those with conventional thyrotoxicosis, but the age range is similar. Patients with autonomously functioning thyroid nodules and those with thyrotoxicosis recurring after antithyroid drug therapy, radioactive iodine or thyroidectomy, have a higher incidence of T3 toxicosis than do unselected patients with hyperthyroidism. Patients with iodine deficiency also have a higher incidence of T3 toxicosis. The reported incidence of T3 toxicosis amongst newly diagnosed thyrotoxic patients varies from 4% to 12.5%; in Sydney it is probably about 5%. It is important to be aware of this form of hyperthyroidism in which the “standard” tests of thyroid function usually give normal results. Direct measurement of the serum T3 level will establish the diagnosis, but when this is not available the T3 suppression test is an adequate screening procedure.