[Case report: persistent fever after SARS-CoV-2 infection]

A 44-year-old man had persistent fever following a severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection. Because of progressive sinus tachycardia, thyroid hormones were measured which showed hyperthyroidism. Thyroid sonography revealed enlargement of the thyroid gland with hypoechoic areas with blurred margins. We diagnosed subacute granulomatous thyroiditis associated with SARS-CoV‑2 infection and initiated therapy with prednisolone. This therapy resulted in rapid improvement of the patient's clinical condition and complete remission after three months.

The Association of Subacute Thyroiditis with COVID-19: a Systematic Review

The multisystem effects of SARS-CoV-2 encompass the thyroid gland as well. Emerging evidence suggests that SARS-CoV-2 can act as a trigger for subacute thyroiditis (SAT). We conducted a systematic literature search using PubMed/Medline and Google Scholar to identify cases of subacute thyroiditis associated with COVID-19 and evaluated patient-level demographics, major clinical features, laboratory findings and outcomes. In the 21 cases that we reviewed, the mean age of patients was 40.0 ± 11.3 years with a greater female preponderance (71.4%). Mean number days between the start of COVID-19 illness and the appearance of SAT symptoms were 25.2 ± 10.1. Five patients were confirmed to have ongoing COVID-19, whereas the infection had resolved in 16 patients before onset of SAT symptoms. Fever and neck pain were the most common presenting complaints (81%). Ninety-four percent of patients reported some type of hyperthyroid symptoms, while the labs in all 21 patients (100%) confirmed this with low TSH and high T3 or T4. Inflammatory markers were elevated in all cases that reported ESR and CRP. All 21 cases (100%) had ultrasound findings suggestive of SAT. Steroids and anti-inflammatory drugs were the mainstay of treatment, and all patients reported resolution of symptoms; however, 5 patients (23.8%) were reported to have a hypothyroid illness on follow-up. Large-scale studies are needed for a better understanding of the underlying pathogenic mechanisms, but current evidence suggests that clinicians need to recognize the possibility of SAT both in ongoing and resolved COVID-19 infection to optimize patient care.