Subacute thyroiditis might be a complication triggered by SARS-CoV-2

Long-Term Impacts of COVID-19 on Thyroid Health: Insights From Clinical Studies

BACKGROUND

COVID-19 emerged in December 2019 and rapidly became a global pandemic. It has since been associated with the progression of various endocrine disorders, including thyroid disease. The long-term effects of this interplay have yet to be explored. This review explores the relationship between COVID-19 and thyroid diseases, emphasizing thyroid gland function and the clinical implications for managing thyroid disorders in infected individuals.

OBJECTIVES

This narrative review intends to provide insight into the scope of research that future clinical studies may aim to address regarding the long-term effects of COVID-19 infection on thyroid health.

METHODS

Keywords including "thyroid disease", "COVID-19", and "long-term" were used to search PubMed and Google Scholar for updated and relevant clinical research.

RESULTS

COVID-19 affects the thyroid gland multifacetedly and includes direct viral invasion, immune-mediated damage, and hypothalamic-pituitary-thyroid axis disruption. Approximately 15% of COVID-19 patients experience thyroid dysfunction, which can present as thyrotoxicosis, hypothyroidism, or non-thyroidal illness syndrome (NTI). Noteworthy findings include inflammatory thyroiditis. Long-term effects, including those observed in children, include persistent hypothyroidism and exacerbated pre-existing thyroid-autoimmune conditions. Management of thyroid disorders in COVID-19 patients requires consideration: anti-thyroid drug (ATD) therapy used to treat hyperthyroidism in COVID-19 patients may need adjustment to prevent immunosuppression. Radioactive iodine (ROI) alternatives and interleukin-6 (IL-6) receptor antagonists could offer potential benefits and should be further explored.

CONCLUSION

Longitudinal follow-ups post-COVID-19 for patients with new and pre-existing thyroid disorders can improve disease outcomes. In addition, pathophysiological research on thyroid dysfunction in COVID-19 may help develop strategies to prevent and alleviate thyroid gland abnormalities post-COVID-19.

Subacute Thyroiditis in Active COVID-19 Infection: A Report of Two Cases With a Systematic Review of the Literature

Subacute thyroiditis (SAT) is a self-limiting inflammatory condition of the thyroid gland with distinct symptoms and a predictable outcome. During the current COVID-19 pandemic, there have been multiple isolated reports of SAT either during the active viral illness or following recovery. Here, we report two such cases of COVID-19 infection presenting with SAT. A 65-year-old male presented with a two-week history of anterior neck pain, odynophagia, high-grade fever (38.9°C), sweating, palpitations, and tremulousness. At physical examination, the patient presented with a slightly increased heart rate and a tender and enlarged thyroid on palpation. Laboratory examination showed high C-reactive protein levels, with elevated erythrocyte sedimentation rate, and thyroid function tests were suggestive of thyrotoxicosis. Ultrasonography showed a heterogeneous thyroid gland with ill-defined hypoechoic areas, and thyroid scintigraphy showed reduced uptake, confirming the diagnosis of SAT. In another case, a 52-year-old male presented with fever, cough, and myalgias, and was diagnosed with mild COVID-19 pneumonia, and managed conservatively. After two weeks, the patient had a recurrence of high-grade fever, odynophagia, palpitations, and tremors. Examination revealed tachycardia, hyperhidrosis, and a tender and enlarged thyroid on palpation. Thyroid function tests revealed low thyroid-stimulating hormone, with normal total T4 and total T3. Ultrasonography examination showed a heterogeneous thyroid gland with bilateral ill-defined hypoechoic areas. In our systematic review, including 103 SAT cases, it has been suggested that SAT should be recognized as an uncommon extra-pulmonary clinical manifestation of COVID-19 infection and clinicians need to be aware of the association. Pending larger multicentric studies, management of the condition has to be on a case-by-case basis.

Subacute thyroiditis with liver dysfunction following coronavirus disease 2019 (COVID-19) vaccination: report of two cases and a literature review

Subacute thyroiditis is a transient inflammatory thyroid disease characterized by neck pain, fever, and typical symptoms associated with thyrotoxicosis. The incidence of subacute thyroiditis is higher in female than in male, and susceptibility is prominent in the 30-50-year age range. The variety of case reports on subacute thyroiditis associated with coronavirus disease 2019 (COVID-19) appears to be increasing, and subacute thyroiditis following COVID-19 vaccination has recently been reported. Herein, we report two cases of subacute thyroiditis that developed after receiving the COVID-19 mRNA vaccine, one of which exhibited remarkable liver dysfunction. The mechanism underlying the development of post-vaccination subacute thyroiditis remains unknown; however, one theory suggests that adjuvants contained in vaccines may play a role in triggering diverse autoimmune and inflammatory responses. Another possibility is the potential cross-reactivity between the coronavirus spike protein target produced by the mRNA vaccine and thyroid cell antigens. Common side effects of the COVID-19 vaccine include pain at the injection site, fever, fatigue, headache, muscle pain, chills, and nausea. These symptoms are usually resolved within a few days. Subacute thyroiditis may present symptoms similar to those of short-term vaccination side effects or exhibit non-specific symptoms, potentially leading to misdiagnosis or underdiagnosis. Therefore, clinicians should be aware of the possible development of subacute thyroiditis after COVID-19 vaccination.