Vaccine-Induced Thrombocytopenia with Severe Headache

This correspondence describes vaccine-induced thrombocytopenia (VIT) with severe headache as a potential precursor to vaccine-induced immune thrombotic thrombocytopenia (VITT) following ChAdOx1 nCoV-19 (AstraZeneca) vaccination. Eleven patients presented with severe headache 5–18 days post-vaccination, accompanied by thrombocytopenia, elevated D-dimer levels, and high anti-PF4-heparin IgG antibodies. Three patients developed intracranial hemorrhage, two of whom had cerebral venous sinus thrombosis (CVST). Notably, delayed or interrupted anticoagulation correlated with thrombotic complications, while early intervention (e.g., high-dose immune globulin or anticoagulation) prevented thrombosis in most cases. The authors propose "pre-VITT syndrome" a prodromal phase marked by headache and thrombocytopenia urging prompt testing (platelet count, D-dimer, anti-PF4 antibodies) and early treatment to avert progression to VITT.

This correspondence describes vaccine-induced thrombocytopenia (VIT) with severe headache as a potential precursor to vaccine-induced immune thrombotic thrombocytopenia (VITT) following ChAdOx1 nCoV-19 (AstraZeneca) vaccination. Eleven patients presented with severe headache 5–18 days post-vaccination, accompanied by thrombocytopenia, elevated D-dimer levels, and high anti-PF4-heparin IgG antibodies. Three patients developed intracranial hemorrhage, two of whom had cerebral venous sinus thrombosis (CVST). Notably, delayed or interrupted anticoagulation correlated with thrombotic complications, while early intervention (e.g., high-dose immune globulin or anticoagulation) prevented thrombosis in most cases. The authors propose "pre-VITT syndrome" a prodromal phase marked by headache and thrombocytopenia urging prompt testing (platelet count, D-dimer, anti-PF4 antibodies) and early treatment to avert progression to VITT.