Immune thrombocytopaenic purpura following the second dose of Pfizer COVID-19 vaccine

Abstract

Immune thrombocytopaenic purpura (ITP) is often a diagnosis of exclusion with presentations ranging widely from asymptomatic patients to those with life-threatening bleeding. Secondary ITP following vaccination is relatively uncommon and underdiagnosed as majority of patients remain asymptomatic. Cases of severe thrombocytopaenia associated with SARS-CoV-2 messenger RNA (ribonucleic acid) vaccinations have been described previously, mostly as isolated occurrences, and typically occurring following the first dose. Here we present a case of severe ITP associated with the second dose of the Pfizer-BioNTech/BNT16B2b2 mRNA vaccine and provide a review of the current literature.