Objective: Graves' disease is an autoimmune thyroid disease that is thought to develop following environmental exposure in patients with genetic predisposition. Our objective is to present the first report of Graves' disease onset immediately following recovery from mild coronavirus disease 2019 (COVID-19), a close temporal occurrence that should be studied further.
Methods: We describe the clinical course and laboratory features, including thyroid function studies, antibody testing, and polymerase chain reaction testing for severe acute respiratory syndrome coronavirus 2.
Results: A 21-year-old woman with prediabetes, obesity, asthma, and gastroesophageal reflux disease presented to the emergency department reporting 3 days of tachycardia, palpitations, anxiety, and shortness of breath. Laboratory investigation revealed a thyroid-stimulating hormone level of 0.01 (0.30-5.00) mcIU/mL with a free thyroxine level of 3.8 (0.6-1.6) ng/dL, prompting endocrinology consultation. On physical examination, she had mild diffuse thyromegaly without tenderness and a history, which included hypothyroidism in her mother. Antibody testing results demonstrated thyroid-stimulating immunoglobulin and thyrotropin receptor antibody levels of 2.6 (<1.3) thyroid-stimulating immunoglobulin index and 17 (0.00-1.75) IU/L, respectively. Sixteen days before presenting to the ED, she was diagnosed with COVID-19 by polymerase chain reaction test after reporting typical symptoms, including fever. Infectious symptoms resolved within 10 days. She achieved clinical and laboratory improvements with a combination of methimazole and beta blocker therapy.
Conclusion: This case documents the occurrence of Graves' thyrotoxicosis following mild symptomatic COVID-19. Whether the preceding infection is coincidental or contributed to GD development requires definitive studies. This presentation may align with the theory of a viral link in the development of autoimmune thyroid disease in those with genetic predisposition.