The silent form of thyroiditis is so named because it’s tricky to diagnose and often avoids detection until symptoms become severe. It is debatable whether this is a unique type of thyroiditis or a type of Hashimoto’s thyroiditis that is not associated with a goiter. Since most forms of autoimmune thyroiditis that present with lymphocytes invading the thyroid gland (lymphocytic thyroiditis) are commonly called Hashimoto’s thyroiditis, the differences between these two labels might be insignificant. Silent thyroiditis runs a painless course but is otherwise similar to subacute viral thyroiditis and essentially the same as Hashitoxicosis. With this version, there are no symptoms or outward signs of infl ammation, but mild thyrotoxicosis still occurs for the same hormone leakage.
There is no evidence that a virus is involved in silent thyroiditis.
There are some who think this type of thyroiditis might be a shortlived autoimmune disorder, like a mini-Hashimoto’s disease. Silent thyroiditis sufferers are usually women, and it commonly occurs postpartum. (Postpartum thyroiditis, discussed in the upcoming section and in Chapter 8, is silent thyroiditis after delivery.)
In the course of the diagnosis, a silent thyroiditis sufferer may be given a radioactive iodine uptake test. The uptake test can reveal the real cause of the hyperthyroidism, showing very low absorption.
As with de Quervain’s thyroiditis, silent thyroiditis usually runs its course and the thyrotoxicosis clears up. Beta-blockers may provide relief from some thyrotoxic symptoms. If a period of hypothyroidism follows the transient episode of thyrotoxicosis, thyroid hormone treatment may be required unless the episode was very brief. Some people with silent thyroiditis become permanently hypothyroid, requiring lifelong thyroid hormone replacement therapy.