Subacute thyroiditis after SARS-Cov2 vaccination: A review of the cases being described and personal experience.

Objective. The present study evaluates the occurrence of subacute thyroiditis in temporal connection with SARS-Cov2 vaccinations described in the literature last year and confirmed by our clinical routine. Methods. Systematic literature search in Medline for studies reporting diagnosis of subacute thyroiditis in temporal connection with vaccinations against Covid 19. Results. The literature search yielded 24 relevant references out of which 22 were "case reports" and two "Letters to the Editor" and encompassed 37 patient cases, in total. They had received a SARS-Cov2 vaccination shortly before the diagnosis (median interval to vaccination six days). In none of these cases, infection of the upper respiratory tract had previously been identified as a classic trigger of the disease. Newly occurring hyperthyroidism and increased laboratory signs of inflammation were described in 78% and 74% of cases, respectively. Atypical clinical pictures (asymptomatic, euthyroid, no inflammation marks) have been observed in both the literature and our patients suspected of thyroid cancer referred to surgery. Conclusions. In times of pandemics and the resulting vaccination, new rapidly occurring sonographic changes in the thyroid gland should be revaluated after 2-3 weeks, or recommended to undergo a fine-needle biopsy, in order to avoid unnecessary surgical interventions.