Sir.—Reporting a case of T3 thyrotoxicosis in a child, Weiss et al (132:374-375, 1978) postulated that in pediatric patients the disease may be more common than indicated by the few reported cases.
We have had the opportunity to study a T3 toxicosis in a 10-year-old girl with diffuse goiter and exophthalmus. Thyroid studies showed normal serum thyroxine (T4) level, raised serum triiodothyronine (T3) level, raised uptake of radioactive iodine by thyroid, and absence of serum thyroid-stimulating hormone response to thyrotrophin-releasing hormone.1 In spite of the fact that both low or high iodide ingestion have been reported as an etiologic factor in some cases of T3 thyrotoxicosis, a detailed dietary history did not disclose data to support such an etiology in our patient. Poor iodination of thyroglobulin,2 interference in the peripherical conversion of T4 to T3,3 or the presence of thyroidstimulating