The term thyroiditis encompasses several variants including Hashimoto's, subacute, postpartum, drug-induced, suppurative, Riedel's and silent thyroiditis (1).
Silent thyroiditis occasionally can recur and usually requires only symptomatic treatment.
In the differential diagnosis of recurrent thyrotoxicosis apart from silent thyroiditis, Hashimoto's thyroiditis, subacute thyroiditis, postpartum thyroiditis (1,4), and factitious thyrotoxicosis should be included.
In a case report by Choe and colleagues, a thyroiditis case initially considered as subacute thyroiditis was finally diagnosed as silent thyroiditis at the third attack and the patient was treated with radioactive 131I ablation after the fourth attack (7).
Postpartum thyroiditis is not different from silent thyroiditis clinically, except that it occurs after pregnancy.
As a conclusion, absence of delivery in the last six months, presence of moderately high anti-TPO, normal serum thyroglobulin levels and recurrent episodes were diagnostic of recurrent silent thyroiditis in our case.
The samples included 41 sera from patients with Graves disease (32 untreated hyperthyroid patients and 9 treated patients) and 42 sera from patients with other thyroid diagnoses, as follows: 13 with Hashimoto thyroiditis, 3 with nodules, 13 with multinodular goiter, 3 with cancer, 2 with silent thyroiditis
, and 8 with no thyroid disease.
Thyroiditis, toxic nodular goiter, thyrotropin-secreting pituitary tumor, ingestion of thyroxine, silent thyroiditis, and therapeutic doses of iodine are other reported causes of thyrotoxic hypokalemic periodic paralysis (3,10-12).
Silent thyroiditis with thyroid-stimulationblocking antibodies (TSBAb).
The antibodies also appear in autoimmune thyroid diseases such as Graves disease, Hashimoto thyroiditis, silent thyroiditis, and subacute thyroiditis (4-7), and nonthyroid autoimmune disease (6).
A case of progressive systemic sclerosis (PSS) with silent thyroiditis and anti-bovine thyrotropin antibodies.