Subacute Thyroiditis in the Time of COVID-19
Article information
First reported in December 2019 in Wuhan, China, coronavirus disease 2019 (COVID-19) has spread rapidly around the world, resulting in 773,119,173 infections and 6,990,067 deaths by the end of December 2023 [1]. Although the primary symptoms of COVID-19 include fever, chills, and respiratory issues, the presence of angiotensin-converting enzyme 2 in thyroid cells [2] has been associated with the development of thyroid disease following COVID-19 infection [3]. Furthermore, there have been reports of thyroid disease occurring as a result of the COVID-19 vaccine [4].
Subacute thyroiditis (SAT) can develop following COVID-19 infection, as well as after receiving a COVID-19 vaccination. The clinical manifestations, which include neck pain, fever, and thyrotoxic symptoms, are similar to those of typical SAT. These symptoms usually appear about 28 days after COVID-19 infection [5,6] and approximately 10 to 14 days after COVID-19 vaccination (Table 1) [7,8].
Summary of Subacute Thyroiditis Following COVID-19 Infection and COVID-19 Vaccination from Systematic Reviews
In a recent study published by Lee et al. [9], the authors compared the incidence of SAT in patients with long COVID to a control group without COVID-19. The risk of SAT was 1.76 times higher in the long COVID group than in the control group. Interestingly, there was no significant difference in the risk of developing SAT between the control group and those with COVID-19 until 6 months post-infection or from the index date. However, after 6 months from the infection or index date, the risk of SAT in the COVID-19 group was 2.3 times higher than in the control group. These findings indicate that the risk of SAT following COVID-19 may persist and even increase in the long term, not just in the immediate aftermath of the infection.
However, the clarity of the study is hindered by the ambiguity surrounding the exclusion of participants who received the COVID-19 vaccine during the enrollment period. As a result, it is uncertain whether the SAT observed in this study is a complication of long COVID or a side effect of the COVID-19 vaccine. To resolve this ambiguity, data from the Korean Disease Control and Prevention Agency COVID-19-National Health Insurance Service (K-COV-N) cohort, which integrates information on Korea’s COVID-19 cases, vaccination records, and National Health Insurance System, could be utilized for further analysis. By conducting an analysis that excludes vaccinated individuals from the cohort of the study of Lee et al. [9], we anticipate obtaining more definitive and accurate results regarding the risk of SAT following long COVID.
Notes
CONFLICTS OF INTEREST
No potential conflict of interest relevant to this article was reported.