Subacute thyroiditis as a post-COVID-19 complication: a systematic review

Introduction: The emergence of Subacute Thyroiditis (SAT) in the wake of COVID-19 has presented a unique set of challenges for clinicians and researchers. This study delves into the intricate interplay between COVID-19 and SAT, examining a wealth of cases from observational studies. Methods: We conducted a comprehensive literature review utilizing PubMed/MEDLINE, EMBASE, and Scopus databases, encompassing studies available up to January 2, 2025. The search strategy incorporated a combination of keywords such as “Subacute Thyroiditis” and “COVID-19,” complemented by synonyms and Mesh terms. Relevant studies, investigating COVID-19-associated SAT were included. Results: After a meticulous review of 964 papers, 46 records were included in the final analysis, consisting of 37 case reports and 9 case series. Our study, covered 75 individuals aged 18 to 85. Investigated patients presenting diverse symptoms, including anterior cervical pain and palpitations, displaying varying timelines from COVID-19 onset to SAT symptoms. Treatment approaches, involving prednisone and non-steroidal anti-inflammatory drugs (NSAIDs), led to recovery in many cases, but some individuals experienced a transition to hypothyroidism. The diagnostic and laboratory investigations across revealed diverse profiles, thyroid imaging findings, inflammatory markers, thyroid function tests, and the presence of anti-thyroid antibodies. Conclusion: The complexity of SAT is emphasized, particularly in the context of COVID-19. The consistent trend toward recovery of thyroid function not only suggests potential treatment efficacy but also emphasizes the necessity for vigilant symptom monitoring, especially in individuals with a history of COVID-19. Future studies should further investigate the details of SAT post-COVID-19, improving approaches to diagnosis, treatment, and patient care.