Subacute Thyroiditis Developing Within 2 Days of Vaccination Against COVID-19 with BNT162b2 mRNA

A 32-year-old woman presented to the outpatient clinic with persistent fever, anterior neck pain, and palpitations over past week which developed 2 days after she had received first dose of Pfizer/BioNTech SARS-CoV-2 mRNA vaccine. On examination, patient’s heart rate was 140 beats per minute thyroid gland tender on palpation. Laboratory studies showed a low serum TSH level elevated free thyroxine. Thyroid ultrasound revealed low-echoic lesions compatible site tenderness. The patient diagnosed subacute thyroiditis treatment initiated acetaminophen propranolol, resulted in symptom resolution within weeks. Clinicians should be aware that may occur few following COVID-19 vaccination, especially patients cervical pain no significant abnormal pharyngeal findings and/or severe palpitations, because differentiating them from early non-specific adverse reactions can challenging.