Immune Thrombocytopenia Following COVID-19 Vaccination in a Pediatric Patient

Immune thrombocytopenia (ITP) is the most common acquired bleeding disorder in children, with further delineation into primary and secondary causes; it is immune-mediated and typically self-limited. Primary ITP is often seen in children with a history of a preceding infection that has subsequently resolved. Additionally, ITP can be seen in children within six weeks of vaccination with measles-mumps-rubella and varicella, and in adults, ITP has developed following messenger RNA (mRNA) vaccination. We present the case of a three-year-old boy who presented with petechiae and purpura eight days after Moderna COVID-19 vaccination and was found to have severe thrombocytopenia with a platelet count of 3,000/mm³. He was thought to have secondary ITP from COVID-19 vaccination. To date, there have been no published reports of ITP presenting in children following mRNA COVID-19 vaccination. This case brings to attention the possible complication of ITP after COVID-19 vaccination with spontaneous resolution without medical intervention and the need for further clinical monitoring of symptoms after COVID-19 vaccination.