Subacute thyroiditis (SAT) is a self-limited inflammatory thyroid disease. It is characterised by neck pain, general symptoms, and thyroid dysfunction. The aetiology of SAT is presumed to be usually viral. With the ongoing pandemic of the SARS-CoV-2 virus and the identification of its endocrinological effects, SARS-CoV-2 should be included in the list of viral triggering factors of SAT. The interlinkage between thyroid hormones, the immune system, and the direct cytotoxic effect of the virus is proposed to play a role in SAT. Here, we report 3 cases of post-COVID-19 thyroiditis, documented on a Tc-99m pertechnetate thyroid scan. Our patients had the clinical manifestations and laboratory findings of thyrotoxicosis, with a thyroid scan supporting the diagnosis of SAT. The diagnosis of SAT on thyroid scan and response to conservative management strengthen the SAT post-COVID-19 infection. SAT is one of the aspects of the covert long COVID syndrome. Clinical features consistent with SAT and a history of recent COVID disease should prompt investigation of a thyroid scan for definitive diagnosis. This case series illustrates the same.
Jain et al. (Tue,) studied this question.