SHM Converge Scientific Abstract ePoster Gallery-T3 Thyrotoxicosis: An Initial Presentation of Graves' Disease

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This case describes a 40-year-old woman with little prior medical care who initially presented with intermittent blurry vision and was found to have bilateral papilledema. Workup showed abnormal thyroid studies and brain MRI findings concerning for posterior reversible encephalopathy syndrome (PRES). In the emergency department, she was noted to have severe hypertension, tachycardia, tachypnea, and acute kidney injury. Thyroid testing showed normal TSH, mildly elevated free T4, and markedly elevated total T3, leading to a diagnosis of T3 thyrotoxicosis.<br /><br />She was treated with nicardipine for hypertensive emergency and later discharged on methimazole, propranolol, lisinopril, and spironolactone. Evaluation for other secondary causes of hypertension was negative. Although she had been taking biotin-containing supplements, which can interfere with thyroid assays, repeat testing after stopping biotin remained abnormal. Positive thyroid-stimulating immunoglobulin and a radioactive iodine uptake scan ultimately confirmed Graves’ disease.<br /><br />The report emphasizes that T3 thyrotoxicosis is an uncommon presentation of hyperthyroidism in which clinical signs of thyrotoxicosis may be present despite normal or minimally elevated TSH and free T4, with disproportionately high T3. Graves’ disease most often affects women aged 20 to 50, and thyroid tests usually show elevated T3 and T4 with suppressed TSH, but this case illustrates that TSH may occasionally be normal. The key clinical lesson is to obtain a full thyroid panel, including total T3, when suspicion for thyrotoxicosis is high, even if the initial TSH is normal.

Asset Subtitle

Nina Rizk

Meta Tag

Author List Nina Rizk

Category Clinical Vignettes

Concept T3 thyrotoxicosis

Concept Triiodothyronine

Concept Graves Disease

Concept Thyroid Function Tests

Concept Thyrotoxicosis

Distinguished Non-Finalist

Presenter Organization University of Rochester Medical Center

Presenting Author Nina Rizk

Track Adult

Keywords

T3 thyrotoxicosis

Graves disease

hypertensive emergency

papilledema

posterior reversible encephalopathy syndrome

thyrotoxicosis

normal TSH

elevated total T3

biotin interference

radioactive iodine uptake scan

T3 thyrotoxicosis

Triiodothyronine

Graves Disease

Thyroid Function Tests

Thyrotoxicosis