Management of thyroiditis in the context of Covid-19: cause-effect and beyond.

Background: The COVID-19 pandemic hit the world in late 2019, and by 2020, everyone was affected. Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) belongs to the beta-coronavirus genre and uses the angiotensin-converting enzyme 2 (ACE2) receptor to penetrate cells. Thyroid cells are rich in such receptors. Therefore, this gland is frequently involved alongside other organs in the COVID-19 disease.

Aim: To describe COVID-19 inflammation and, eventually, dysregulations of normal thyroid function in a case series of patients diagnosed in a tertiary endocrinology care centre.

Patients And Methods: We described subacute thyroiditis cases related to COVID-19 infection or vaccination against SARS-CoV2 infection (clinical manifestations and evolution). We also reviewed the literature data regarding COVID-19 infection or vaccination implications in thyroid pathology.

Results: The literature describes two types of thyroid involvement in SARS-CoV2 infection or vaccination: subacute thyroiditis (SAT) and non-thyroidal illness syndrome (NTIS). In our case series, 5 patients (3 males), aged 41-54 years, developed the classical clinical manifestation of SAT related to COVID-19 infection (3 patients, concomitantly to upper respiratory infection or a few weeks apart) or anti-SARS-CoV2 ARNm vaccination (1-2 weeks after the vaccine administration). Clinical, laboratory and imaging findings and the evolution (steroid anti-inflammatory treatment used in 4/5 cases) were unremarkable compared to other SAT etiologies.

Conclusion: We found no differences between the "typical" viral and post-COVID-19 SAT regarding clinical presentation, severity, response to treatment, and thyroid function alteration. The only remarkable difference is the association of SAT with anti-SARS-CoV2 ARNm vaccination.