endocrine and metabolic disorders
Subacute Thyroiditis
Diagnosis of Subacute Thyroiditis
Clinical findings Free thyroxine (T4) and thyroid-stimulating hormone (TSH) levels Erythrocyte sedimentation rate (ESR) Radioactive iodine uptake 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 Testing of Thyroid Function 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 Hyperthyroidism . 