Clinical Aspects in Subacute Thyroiditis: A Real-Life Study on 226 Cases in Greece Amid the COVID-19 Pandemic.

This study aimed to evaluate various therapeutic approaches, identify potential predictive factors for the recurrence and development of hypothyroidism, and examine specific clinical and laboratory characteristics of patients with subacute thyroiditis (SAT) due to SARS-CoV-2 infection. We retrospectively analyzed the medical records of 226 patients with confirmed SAT diagnosed from January 2020 to November 2022. The mean age was 48.01 ± 0.75 years, and the F/M ratio was 2.3/1. At the end of the follow-up period, 69 patients (32.1%) had developed hypothyroidism. Treatment duration was significantly shorter with nonsteroidal anti-inflammatory drugs (NSAIDs) (17.40 ± 2.56 days), while time-to-symptom relief was shorter with glucocorticoids (CGs). Recurrence was observed only in those treated with corticosteroid preparations (14.1%). C-reactive protein levels at treatment discontinuation were higher in patients who experienced SAT recurrence, while the coexistence of Hashimoto's thyroiditis was a significant predictive factor for the development of hypothyroidism. The TSH value at the time of treatment withdrawal >4.12 μIU/mL showed optimal sensitivity and specificity for the prediction of permanent hypothyroidism. Regarding COVID-19, 34 patients (15%) experienced related SAT, with similar clinical manifestations of the disease but a higher BMI and shorter time-to-symptom relief. In conclusion, GCs administration alleviated acute symptoms earlier during the onset of SAT, whereas NSAIDs had a shorter treatment duration, and both regimens could not prevent the development of delayed hypothyroidism. The clinical characteristics of SAT due to COVID-19 infections were similar to those of typical SAT disease.