A 38-year-old woman presents with acute onset severe thyroid pain, fever, and dysphagia for 3 days. On examination, the thyroid is tender and enlarged. TSH is 0.2 mIU/L (low), free T4 is elevated at 28 pmol/L, and ESR is 95 mm/hr. Thyroid peroxidase (TPO) antibodies are negative. What is the most appropriate next step in management?

Explanation

## Diagnosis: Acute Suppurative (Bacterial) Thyroiditis vs De Quervain's Thyroiditis The clinical presentation—acute onset severe pain, fever, dysphagia, tender enlarged thyroid, elevated inflammatory markers (ESR 95), and suppressed TSH with elevated free T4—is classic for **de Quervain's (subacute granulomatous) thyroiditis**. The negative TPO antibodies exclude autoimmune thyroiditis. ### Key Clinical Features of De Quervain's Thyroiditis | Feature | Finding | Significance | |---------|---------|---------------| | **Onset** | Acute (days to weeks) | Often follows viral URI | | **Pain** | Severe, pleuritic | Hallmark symptom | | **Fever** | Present | Inflammatory response | | **TSH** | Low (thyroid hormone release) | Thyroiditis phase | | **Free T4/T3** | Elevated | Follicular destruction releases hormone | | **TPO antibodies** | Negative | Rules out Hashimoto's | | **ESR** | Markedly elevated (>50) | Intense inflammation | | **FNAC** | Granulomas with giant cells | Diagnostic but rarely needed | ### Management Algorithm for De Quervain's Thyroiditis ```mermaid flowchart TD A[De Quervain's Thyroiditis Confirmed]:::outcome --> B{Severity of Symptoms?}:::decision B -->|Mild pain| C[NSAIDs: Aspirin 650 mg QID or Ibuprofen 400 mg TID]:::action B -->|Moderate-severe pain| D[NSAIDs + Beta-blocker for symptomatic relief]:::action D --> E[Propranolol 20-40 mg TID for palpitations/tachycardia]:::action B -->|Severe, unresponsive to NSAIDs| F[Corticosteroids: Prednisolone 20-40 mg daily]:::action C --> G[Repeat TFTs in 2-4 weeks]:::action E --> G F --> G G --> H{Thyroid Function Normalized?}:::decision H -->|Yes| I[Taper NSAIDs/steroids; observe for hypothyroid phase]:::action H -->|No| J[Continue current therapy; monitor for transition to hypothyroidism]:::action ``` ### Why Propranolol + High-Dose Aspirin? **Key Point:** De Quervain's thyroiditis is **self-limited** and does NOT require immunosuppression or antibiotics (it is viral/inflammatory, not bacterial). 1. **Aspirin (high-dose, e.g., 650 mg QID)** — First-line NSAID for pain and inflammation; also has anti-inflammatory properties beyond analgesia. 2. **Propranolol 20–40 mg TID** — Controls tachycardia and palpitations from excess thyroid hormone release; does NOT affect thyroid function. 3. **Repeat TFTs in 2 weeks** — Monitors disease progression; thyroid function typically normalizes over 4–12 weeks as inflammation resolves. 4. **No levothyroxine yet** — TSH is suppressed and free T4 is elevated; thyroid hormone replacement is contraindicated in the acute phase. Hypothyroidism may develop later (transient or permanent in ~5% of cases). ### Natural History of De Quervain's Thyroiditis **High-Yield:** The disease evolves through three phases: 1. **Thyrotoxic phase (weeks 1–4):** Follicular destruction → hormone release → elevated free T4/T3, suppressed TSH, symptoms of hyperthyroidism. 2. **Euthyroid phase (weeks 4–12):** Hormone stores depleted, TSH normalizes. 3. **Hypothyroid phase (weeks 12+):** Transient (most common) or permanent hypothyroidism; may require levothyroxine. **Clinical Pearl:** Patients often report preceding upper respiratory tract infection (viral trigger). The severe pain is pathognomonic and distinguishes de Quervain's from painless thyroiditis (postpartum, silent, drug-induced). ### Why NOT Corticosteroids First-Line? Corticosteroids are reserved for: - Severe pain unresponsive to NSAIDs (after 1–2 weeks of aspirin). - Rare cases of acute suppurative (bacterial) thyroiditis (which this patient does NOT have — no pus, no focal abscess, no immunocompromise). Early steroid use risks prolonging the disease and masking bacterial infection if present. [cite:Harrison 21e Ch 405]