Subacute thyroiditis, also known as De Quervain's thyroiditis or giant cell thyroiditis, is more commonly observed in women aged 30 to 40. It is often secondary to viral upper respiratory infections and is a common cause of anterior neck swelling and thyroid pain. Histopathological examination typically reveals infiltration by white blood cells, lymphocytes, and foreign body giant cells, along with the presence of giant cell granulomas surrounding affected thyroid follicles.
Clinical Manifestations
Common presentations include sudden thyroid swelling, firmness, and pain in the anterior neck, radiating toward the ipsilateral ear and temple region. The condition often starts on one side of the thyroid and rapidly spreads to other parts of the gland. Patients may experience fever and an accelerated erythrocyte sedimentation rate (ESR). The disease course lasts approximately 3 months, and thyroid function is commonly preserved after recovery.
Diagnosis
A history of upper respiratory infection 1 to 2 weeks prior to onset is often noted. Within the first week of the illness, partial destruction of follicular cells may cause a slight elevation in basal metabolic rate and increased serum T3 and T4 levels. However, thyroid uptake of radioactive iodine (131I) is markedly reduced (a "discordance phenomenon"). The efficacy of prednisone treatment also supports the diagnosis. Fine-needle aspiration biopsy identifying characteristic cells can provide a definitive diagnosis.
Treatment
This is a self-limiting condition with a favorable prognosis. Mild cases can be managed with nonsteroidal anti-inflammatory drugs (NSAIDs). More severe cases may require treatment with prednisone for 1 to 2 months. For recurrent episodes following medication withdrawal, radiotherapy offers a more lasting effect. Antibiotics are ineffective in the treatment of this condition.