Thyroid Disorders USMLE Step 1 Practice Question
A 31-year-old woman presents with sudden-onset severe neck pain, fever (38.9°C), and malaise. Vital signs show tachycardia (HR 102/min) and tachypnea (RR 20/min). Laboratory studies reveal elevated inflammatory markers (ESR 68 mm/hr, CRP 12.5 mg/dL), TSH 6.2 mIU/L, and free T4 1.9 ng/dL (elevated). Thyroid ultrasound demonstrates heterogeneous echotexture with hypoechoic areas. She denies recent upper respiratory infection. Which of the following best describes the likely pathophysiology?
Answer choices
- AIodine-induced suppression of thyroid hormone synthesis
- BBacterial infection of thyroid parenchyma with abscess formation
- CAutoimmune destruction of thyroid follicles with TSH receptor antibodies
- DThyroid peroxidase antibodies causing chronic inflammation
- EViral-mediated thyroid inflammation causing thyroid hormone release into circulationCorrect answer
- FExcessive iodine intake leading to Wolff-Chaikoff effect and subsequent thyroid hormone depletion
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