Subacute thyroiditis during the COVID-19 pandemic: a prospective study

Area of Science:

• Endocrinology
• Infectious Diseases
• Virology

Background:

• Subacute thyroiditis (SAT) is a destructive thyroid inflammation often linked to viral infections.
• Recent reports suggest an association between SAT and SARS-CoV-2 infection and vaccination.

Purpose of the Study:

• To prospectively evaluate SAT cases at a tertiary center over 16 months during the COVID-19 pandemic.
• To assess the relationship between SAT cases and SARS-CoV-2 infection/vaccination.
• To compare pandemic-era SAT incidence with pre-pandemic data.

Main Methods:

• Prospective study conducted from March 2020 to July 2021.
• SAT diagnosis based on classical criteria; SARS-CoV-2 and respiratory viral panel testing performed.
• Patients categorized into COVID-19-associated SAT (CoV-SAT), vaccine-associated SAT (Vac-SAT), and non-associated SAT (NonCoV-SAT).

Main Results:

• Out of 64 SAT patients, 18.8% were CoV-SAT, 9.3% were Vac-SAT, and 71.9% were NonCoV-SAT.
• SARS-CoV-2 RT-PCR was negative in most cases at diagnosis, with two positive on re-testing.
• Vac-SAT group exhibited milder symptoms and easier treatment compared to CoV-SAT and NonCoV-SAT groups.

Conclusions:

• The overall incidence of SAT remained similar during the pandemic compared to pre-pandemic periods.
• A notable proportion of SAT cases were associated with SARS-CoV-2 exposure (infection or vaccination).
• COVID-19 was the initial presentation of SAT in three patients; vaccine-related SAT cases were milder and required less corticosteroid treatment.