Subacute thyroiditis following COVID-19 vaccination: Case presentation.

Area of Science:

• Endocrinology and immunology
• Vaccine safety and adverse events
• Thyroid disease research

Background:

• Subacute thyroiditis (SAT) is an inflammatory thyroid condition, often viral, that can be drug-induced, including by COVID-19 vaccines.
• COVID-19 infection itself is linked to thyroid damage through direct viral action, euthyroid sick syndrome, or immune responses.
• While generally self-limiting, SAT can lead to permanent hypothyroidism in about 15% of cases.

Observation:

• A 37-year-old male presented with neck pain and fever 23 days post-second Pfizer-BioNTech mRNA COVID-19 vaccine.
• Physical examination revealed a tender, enlarged thyroid gland without lymphadenopathy and mild tachycardia.
• The patient had no prior history of autoimmune or other diseases.

Findings:

• Initial lab results showed mild leukocytosis, normocytic anemia, thrombocytosis, elevated lactate dehydrogenase, and decreased iron.
• Thyroid function and morphology fully recovered following the episode of post-vaccine SAT.
• This case represents a rare occurrence of SAT developing several weeks after COVID-19 vaccination.

Implications:

• Healthcare professionals should promptly report cases of SAT potentially linked to COVID-19 vaccination.
• Further research is needed to elucidate the immunopathogenesis of COVID-19-associated thyroiditis.
• Understanding the impact of COVID-19 immunization on thyroid health is crucial for vaccine safety monitoring.