Immune Thrombocytopenia Exacerbation After COVID-19 Vaccination in a Young Woman

The coronavirus disease 2019 (COVID-19) pandemic is one of the greatest health concerns worldwide. Safe and effective COVID-19 vaccines are urgently needed and have been rapidly approved. COVID-19 vaccine-induced thrombocytopenia was reported as a rare adverse effect in the Vaccine Adverse Events Reporting System. A 25-year-old woman, who was previously diagnosed with immune thrombocytopenia (ITP, stage I), had exacerbated severe thrombocytopenia (platelet count of 6,000/μL) with a headache, joint pain, general fatigue, and bleeding tendency three days after receiving her second dose of the Pfizer BioNTech COVID-19 vaccine. Pulsed high-dose dexamethasone therapy rapidly ameliorated the ITP. Although it is difficult to confirm a causal association between Pfizer BioNTech COVID-19 vaccination and ITP exacerbation, abrupt onset of ITP exacerbation after vaccination suggests that the ITP may be vaccination-induced thrombocytopenia exacerbation. Rare but severe adverse events such as ITP may be observed, depending on increased numbers of individuals who receive COVID-19 vaccines worldwide. Further investigation is needed to clarify the mechanisms of COVID-19 vaccine-induced ITP.