Subacute Thyroiditis for Practical Nurses

Subacute thyroiditis, also known as De Quervain thyroiditis, subacute granulomatous thyroiditis, or giant cell thyroiditis, is a self-limiting inflammatory disorder of the thyroid gland most commonly triggered by a viral upper respiratory infection. It is the most common cause of a painful thyroid gland. The condition occurs when a viral infection (most commonly Coxsackievirus, adenovirus, mumps, influenza, or Epstein-Barr virus) triggers an inflammatory immune response within the thyroid gland. The inflammatory infiltrate consists of multinucleated giant cells, lymphocytes, and macrophages that form characteristic granulomas within the thyroid follicles. This inflammatory destruction of thyroid follicles causes the release of preformed thyroid hormones (T3 and T4) and thyroglobulin from damaged follicular cells into the bloodstream. The disease follows a classic TRIPHASIC course. Phase 1 (Thyrotoxic phase, lasting 3-6 weeks): Destruction of thyroid follicles releases stored thyroid hormones, causing elevated serum T3 and T4 with suppressed thyroid-stimulating hormone (TSH). Patients experience symptoms of thyrotoxicosis (tachycardia, anxiety, tremor, heat intolerance, weight loss) along with a painful, tender, and enlarged thyroid gland. The pain often radiates to the jaw, ear, or throat and may be...