SUBACUTE THYROIDITIS IN A PATIENT WITH CORONAVIRUS DISEASE 2019

OBJECTIVE: Subacute thyroiditis (SAT) is an inflammatory disorder of the thyroid gland that causes destructive thyrotoxicosis and is attributed to a viral or post-viral response. SARS-CoV-2 is a novel coronavirus that caused a global pandemic in 2020. We present a case that suggests that there may be a relationship between SAT and corona-virus disease 2019 (COVID-19). METHODS: We describe the clinical findings, thyroid function tests, and neck ultrasound of a patient presenting with anterior neck pain. RESULTS: A 47-year-old, Filipino female presented with anterior neck pain associated with neck tenderness and goiter. She did not have fever or respiratory symptoms but had right lower lobe pneumonia on chest radiograph. Thyroid function tests were consistent with subclinical hyperthyroidism with thyroid-stimulating hormone of 0.05 μIU/mL (reference range is 0.47 to 4.68 μIU/mL), free thyroxine of 1.68 pg/mL (reference range is 0.78 to 2.19 pg/mL), and total triiodothyronine of 1.4 ng/mL (reference range is 0.97 to 1.69 ng/mL). Anti-thyroid peroxidase, anti-thyroglobulin, and thyroid-stimulating hormone receptor antibodies were negative. Neck ultrasound showed heterogenous thyroid tissues with normal vascularity. Reverse transcription-polymerase chain reaction for SARS-CoV-2 using nasopharyngeal and oropharyngeal swabs were positive. The patient was diagnosed as having SAT and was treated with mefenamic acid, which was later switched to celecoxib. Ceftriaxone and hydroxychloroquine were started for COVID-19 pneumonia. Complete resolution of symptoms and primary hypothyroidism occurred after 2 months. CONCLUSION: SAT may be a presenting symptom or a sequela of COVID-19. Histopathology studies and definitive documentation of the virus in thyroid tissues may be required to confirm the relationship between SAT and COVID-19.