[Thyroid and SARS-CoV-2]

There are several interactions between a SARS-CoV‑2 infection and the thyroid, bidirectionally in both directions. In severe COVID-19 infection, changes in thyroid hormone levels are a marker for poorer prognosis. SARS-CoV‑2 appears to interact directly with thyrocytes as well as modulate the immune system and trigger autoimmune thyroid disease. As early as 2020, SARS-CoV‑2 associated thyroiditis was described in patients with COVID-19, which is similar to subacute thyroiditis but typically painless. There are now a wide variety of reports on the occurrence of chronic autoimmune thyroiditis and Graves' disease following both viral infection and vaccination. Existing thyroid disease does not appear to be associated with either a higher risk of SARS-CoV‑2 infection or a more severe disease course. The present paper summarizes the current knowledge regarding the thyroid gland and SARS-CoV‑2.