Subacute Thyroiditis

There is pain in the anterior neck and fever. Neck pain characteristically shifts from side to side and may settle in one area, frequently radiating to the jaw and ears. It is often confused with dental pain, pharyngitis, or otitis and is aggravated by swallowing or turning of the head. Symptoms of hyperthyroidism are common early in the disease because of hormone release from the disrupted follicles. There is more lassitude and prostration than in other thyroid disorders. On physical examination, the thyroid is asymmetrically enlarged, firm, and tender.

Diagnosis is primarily clinical, based on finding an enlarged, tender thyroid in patients with the appropriate clinical history. Thyroid testing with TSH and at least a free T4 measurement is usually also done. Radioactive iodine uptake should be measured to confirm the diagnosis.

Laboratory findings Laboratory Testing of Thyroid Function The thyroid gland, located in the anterior neck just below the cricoid cartilage, consists of 2 lobes connected by an isthmus. Follicular cells in the gland produce the 2 main thyroid hormones... read more early in the disease include an increase in free T4 and triiodothyronine (T3), a marked decrease in TSH and thyroid radioactive iodine uptake (often 0), and a high ESR. After several weeks, the thyroid is depleted of T4 and T3 stores, and transient hypothyroidism develops accompanied by a decrease in free T4 and T3, a rise in TSH, and recovery of thyroid radioactive iodine uptake. Weakly positive thyroid antibodies may be present. Measurement of free T4, T3, and TSH at 2- to 4-week intervals identifies the stages of the disease.

When the diagnosis is uncertain, fine-needle aspiration biopsy is useful. Thyroid ultrasonography with color Doppler shows multiple irregular sonolucent areas and reduced blood flow in contrast with the increased flow of Graves disease Hyperthyroidism Hyperthyroidism is characterized by hypermetabolism and elevated serum levels of free thyroid hormones. Symptoms include palpitations, fatigue, weight loss, heat intolerance, anxiety, and tremor... read more .

Subacute thyroiditis is self-limited, generally subsiding in a few months; occasionally, it recurs and may result in permanent hypothyroidism Hypothyroidism Hypothyroidism is thyroid hormone deficiency. Symptoms include cold intolerance, fatigue, and weight gain. Signs may include a typical facial appearance, hoarse slow speech, and dry skin. Diagnosis... read more when follicular destruction is extensive.

Mild discomfort (eg, sore throat, mild neck tenderness and muscle aches, low-grade fever), is treated with high doses of aspirin or NSAIDs. In moderately or severely symptomatic cases (eg, high fever, tachycardia, shortness of breath), corticosteroids (eg, prednisone 15 to 30 mg orally once a day, gradually decreasing the dose over 3 to 4 weeks) eradicate all symptoms within 48 hours.

Bothersome hyperthyroid symptoms may be treated with a short course of a beta-blocker. If hypothyroidism is pronounced or persists, thyroid hormone replacement therapy may be required, rarely permanently.