Deep vein thrombosis as thrombotic sequelae of vaccine-induced thrombotic thrombocytopenia

Administration of the ChAdOx1 nCoV-19 (AstraZeneca) vaccination has recently been associated with rare, unusual cases of thrombotic events. We report a case of a 55-year-old woman who presented to hospital with headaches, petechial rashes and bruising—7 days after receiving her first vaccine dose. Blood tests showed low platelets, a markedly high d-dimer and positive anti-platelet factor 4 antibodies. Computed tomography (CT) of head and venogram showed features consistent with venous sinus thrombosis. She was immediately started on IV pooled immunoglobulin therapy, high-dose prednisolone and full anticoagulation. Subsequent magnetic resonance imaging of head and venogram supported the initial CT findings, with features suggestive of a small-volume venous sinus thrombosis. Additionally, CT pulmonary angiogram revealed a right-sided segmental pulmonary embolism. Our case highlights the importance of increased awareness of this complication after covid vaccination and how searching for distal thrombotic events and liaison with tertiary centres influence clinical outcomes.