| Summary: | A 40-year-old Japanese woman presented to the outpatient clinic with fever and palpitations 2 days after receiving the
influenza vaccine (Influenza HA Vaccine ‘KMB’®) following the second dose of coronavirus disease 2019 (COVID-19) vaccine
(COVID-19 vaccine Moderna intramuscular injection®). At the first visit, the patient presented with a swollen thyroid gland
with mild tenderness, and she was diagnosed with subacute thyroiditis (SAT) based on the presence of thyrotoxicosis (free
T3: 5.42 pg/mL; free T4: 2.34 ng/dL; and thyroid-stimulating hormone (TSH): <0.01 μIU/mL), a high C-reactive protein level
(5.77 mg/dL), a negative TSH receptor antibody, and characteristic ultrasound findings. The patient’s human leukocyte
antigen types were A2, A11, B35, B51, DR4, and DR1403. Prednisolone (15 mg/day) was given as an initial dose, after which
the fever subsided, and the dose was tapered and discontinued after 6 weeks. The patient was thought to have developed
SAT due to influenza vaccination. SAT after influenza vaccination may be overlooked. For patients with SAT, it is necessary
to obtain information regarding their vaccination history.
|
|---|