'Silent' subacute thyroiditis

To the Editor.—

In response to the report by Morrison and Caplan, found in the JanuaryArchives(138:45-48, 1978), we do not deny the existence of painless or atypical subacute thyroiditis. Neither do we claim, as Morrison and Caplan do, that the association of thyrotoxicosis, a low radioactive iodine uptake (RAIU), and a nontender thyroid gland is characteristic of subacute thyroiditis (typical "atypical" subacute thyroiditis?). The features not usually associated with subacute thyroiditis that were common to our reported cases and theirs, such as a normal ESR, painless thyroid glands, and occasional progression to hypothyroidism, led us to perform biopsies in a attempt to better define the disease process. Rather than confirm a clinical impression, Morrison and Caplan would allow for an atypical clinical presentation of subacute thyroiditis in these cases, but have rigorously defined criteria for the clinical presentation of Hashimoto's thyroiditis. This exercise completed, the authors classify our