COVID-19-associated thyroid diseases

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:

Overview

COVID-19 has been found to affect several organs and body systems, including the endocrine system, with short-term and possible long-term consequences.

Classification

There is no established system for the classification of COVID-19-associated thyroid disorders.

Pathophysiology

The exact pathogenesis of COVID-19-associated thyroid diseases is not fully understood. However, the following hypotheses have been suggested for the development of thyroid dysfunction in COVID-19 patients.

• Angiotensin-converting enzyme 2 (ACE2) receptors are essentially involved in SARS-CoV-2 internalization into host cells. the thyroid gland is amongst the organs which have the highest levels of ACE2 expression and activity. Therefore, following SARS-CoV-2 infection, thyroid damage could result from either a direct or immune-mediated injury.

• COVID-19 may also cause an immune system imbalance and in severe cases a cytokine storm, which may break immunotolerance in susceptible patients, leading to new onset of immune-mediated thyroiditis, exacerbating a previous thyroid disease, or inducing a recurrence of thyroid disease.

Causes

Coronavirus disease 2019 (COVID-19) caused by a novel coronavirus called SARS-CoV-2 is the cause of COVID-19-associated thyroid diseases.

Risk Factors

There are no established risk factors for COVID-19-associated thyroid diseases.

Screening

There is insufficient evidence to recommend routine screening for COVID-19-associated thyroid diseases.

Natural History, Complications, and Prognosis

A number of observational studies have shown that COVID-19 infection may be linked to some thyroid diseases, including:

• Subacute thyroiditis
• Graves’ disease
• Non-thyroidal illness or euthyroid sick syndrome
• Thyrotoxicosis
• Hashimoto’s thyroiditis

Diagnosis

Diagnostic Study of Choice

The diagnosis of COVID-19-associated thyroid diseases is made based on the thyroid function test (TFT), which measures serum levels of triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH).

Electrocardiogram

• There are no ECG findings associated with COVID-19-associated thyroid disease.
• However, the following findings may be seen on ECG in patients with thyrotoxicosis:
  • Tachycardia, ...

X-ray

There are no x-ray findings associated with COVID-19-associated thyroid diseases.