What type of thyroiditis is primarily caused by a viral infection?

De Quervain thyroiditis, also known as subacute thyroiditis, is primarily linked to viral infections, particularly after viral illnesses such as mumps or influenza. This form of thyroiditis is characterized by a painful, inflamed thyroid gland and often presents with symptoms of fever, malaise, and neck pain. The inflammation results in temporary hyperthyroidism due to the release of stored thyroid hormones from the damaged thyroid tissue, followed by a potential period of hypothyroidism as the condition resolves.

In contrast, other forms of thyroiditis, such as Hashimoto's thyroiditis, are autoimmune in nature and not directly caused by viral infections, while Graves' disease is an autoimmune hyperthyroid condition unrelated to infectious causes. Acute thyroiditis can be related to bacterial infections but is not primarily associated with the viral etiology that characterizes De Quervain thyroiditis. This distinction solidifies De Quervain thyroiditis as the correct choice when discussing thyroiditis caused by a viral infection.