WBR0946
| Author | PageAuthor::William J Gibson |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Immunology, MainCategory::Pharmacology |
| Sub Category | SubCategory::Endocrine |
| Prompt | [[Prompt::A 36-year-old man presents to his primary care physician for anxiety, palpitations and insomnia over the past week. The patient reports some dysphagia when swallowing, and has lost some weight. The physical exam is notable for a heart rate of 110. Radionuclide thyroid scan reveals deceased uptake. Which of the following is the most appropriate therapy for this patient?]] |
| Answer A | AnswerA::Methimazole |
| Answer A Explanation | AnswerAExp::Methimazole is an anti-thyroid drug that inhibits thyroperoxidase, an enzyme essential for the synthesis of T4. Because De Quervain’s thyroiditis causes hypothyroidism eventually, an anti-thyroid drug would be inappropriate. |
| Answer B | AnswerB::Propylthiouracil |
| Answer B Explanation | [[AnswerBExp::Propylthiouracil (PTU) is an anti-thyroid drug that inhibits thyroperoxidase, an enzyme essential for the synthesis of T4. It also inhibits the conversion of T4 to T3 peripherally. Because De Quervain’s thyroiditis causes hypothyroidism eventually, an anti-thyroid drug would be inappropriate.]] |
| Answer C | AnswerC::Surgery |
| Answer C Explanation | AnswerCExp::Because inflammatory damage to thyroid tissue causes eventual hypothyroidism in De Quervain’s thyroiditis, thyroidectomy would be inappropriate. |
| Answer D | AnswerD::Aspirin |
| Answer D Explanation | AnswerDExp::Patients with De Quervain’s thyroiditis should be treated with NSAIDs to decrease inflammation and a beta-blocker to manage the symptoms of hyperthyroidism in the acute phase. |
| Answer E | AnswerE::Levothyroxine |
| Answer E Explanation | AnswerEExp::At this stage, the patient is displaying symptoms of hyperthyroidism. Eventually, patients with De Quervain’s thyroiditis return to a euthyroid state. |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::The patient in this vignette is suffering from De Quervain’s thyroiditis, a subacute thyroiditis that resolves over time. Patients typically show symptoms of hyperthyroidism followed by hypothyroidism. A hyperthyroid period occurs as the follicles are destroyed, releasing abundant colloid and thyroid hormone into the circulation. Patients typically then become hypothyroid as the pituitary reduces TSH production and the inappropriately released colloid is depleted before patients resolve to a euthyroid state. In contrast to other inflammatory thyroid conditions, the thyroid may become enlarged and tender, causing dysphagia.
Classically, multi-nucleated giant cells are present and in some cases, patients will test positive for anti-thyroid antibodies. The clinical presentation during the hyperthyroid phase can mimic those of Diffuse Toxic Goiter or Graves' disease. In such cases, a radionuclide thyroid uptake and scan can be helpful, since subacute thyroiditis will result in decreased isotope uptake, while Graves' disease will generally result in increased uptake. The exact etiology of the condition is unknown, but it often develops following viral infections. Patients typically respond to NSAIDs and beta-blockers. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Thyroid, WBRKeyword::Thyroiditis, WBRKeyword::Autoimmune |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |