Abstract
R
A 57-year-old woman with no medical history received the first dose of the Pfizer-BioNTech SARS-CoV-2 vaccine 34 days before presentation, with associated fatigue, nausea, chills, and myalgias lasting 1.5 days. She received the second dose 13 days before presentation, and within 24 hours had recurrence of her symptoms associated with new progressive anterior neck pain and swelling. She was referred to the hospital by her outpatient provider for thyrotropin (TSH) 0.009 μU/mL, thyroxine (T4) free 2.6 ng/dL, and T4 total 17.4 mcg/dL (outpatient normal ranges [NRs] unavailable). On hospital arrival, she was febrile to 38.3°C with a pulse of 137 beats/min. Examination revealed right thyroid gland enlargement with diffuse tenderness, and no proptosis, lid lag, or periorbital edema. Laboratories showed TSH <0.008 μU/mL (NR: 0.4–4.2), free T4 1.92 ng/dL (NR: 0.8–1.5), triiodothyronine (T3) total 137 ng/dL (NR: 87–178) with thyrotropin receptor antibody <1.10 U/L (NR: 0–1.75), thyroid stimulating immunoglobulin <0.10 U/L (NR: 0–0.55), thyroid peroxidase antibody <0.5 U/mL (NR: 0–5.6), and thyroglobulin antibody 3.4 U/mL (NR: 0–4.1). Thyroid ultrasound showed an asymmetrically enlarged hypervascular heterogeneous right thyroid lobe suggestive of thyroiditis. She was treated with propranolol and ibuprofen and later started on prednisone as an outpatient.
There is likely a causal relationship between this patient's thyroiditis with thyrotoxicosis and the COVID-19 mRNA vaccine, given the condition's temporal relationship with the vaccine in a previously healthy patient with no alternative suspected cause. We reviewed the Vaccine Adverse Event Reporting System for thyroid dysfunction after the COVID-19 vaccine, and there is one case (922030) of a 46-year-old woman of “thyroiditis with hyperthyroidism,” who developed fever, neck pain, and tachycardia 10 days postvaccine (1). Cases 1039886 and 984402 have insufficient information but may involve postvaccine hyperthyroidism. Rare reports have linked subacute thyroiditis to varying influenza vaccines (2 –4), and immune dysregulation has been speculated as contributory to a thyroid inflammatory cascade. A rat model incidentally developed lymphoid thyroiditis after an experimental Group A streptococcal vaccine (5). Clinicians should recognize the potential for thyroiditis as an adverse effect of SARS-CoV2 mRNA vaccines. Although we suspect this reaction is idiosyncratic and rare, studies are needed to better understand the incidence and underlying mechanisms of thyroiditis in this context.
Authors' Contributions
J.S. wrote the original draft. E.A., A.C., and R.S. reviewed and edited the article. M.R. investigated the study.
Footnotes
Author Disclosure Statement
No competing financial interests exist.
Funding Information
No funding was received for this article.