Manifestations of thyroid disease post COVID-19 illness: Report of Hashimoto thyroiditis, Graves’ disease, and subacute thyroiditis

Objective: We present three cases of thyroid dysfunction such as Hashimoto thyroiditis, Graves’ disease and subacute thyroiditis which developed few weeks after resolution of acute phase of COVID -19 infection in patients with no prior thyroid disease. Methods: We discuss clinical presentation, diagnostic evaluation and subsequent management and follow-up in three patients. Results: All three patients tested positive for COVID-19 infection prior to diagnosis. Patient 1. A 38-year-old female developed hypothyroidism 6 weeks after COVID-19 infection, confirmed by TSH 136 mIU/L (range 0.34–5.6), free T4 level 0.2 ng/dL (range 0.93–1.7). Patient 2. A 33-year-old female developed Graves’ disease 8 weeks after COVID-19 infection, with a TSH <0.01 mIU/L (range 0.4–4.5), Free T4 2.1 ng/dl (range 0.8–1.8), total T3 216 ng/dl (range 76–181), elevated TSI 309 (normal