Case Report: Thrombotic and haemorrhagic disseminated intravascular coagulation in COVID-19

BackgroundCOVID-19-associated coagulopathy has been predominantly characterised as a hypercoagulable state with fibrinolytic shutdown. However, the full phenotypic spectrum of disseminated intravascular coagulation (DIC) in COVID-19 remains incompletely characterised. This report adds two cases demonstrating that COVID-19-associated DIC can manifest as two distinct phenotypes at opposite ends of the coagulation spectrum.Case summaryWe report two cases of severe COVID-19 with diametrically opposed DIC phenotypes. Case 1: a 23-year-old immunosuppressed male with SARS-CoV-2 bloodstream and central nervous system infection developed haemorrhagic DIC, characterised by severe hypofibrinogenemia (0.76 g/L), markedly elevated PIC (>40 μg/mL), and preserved platelet counts (>100 × 109/L). He was successfully treated with titrated tranexamic acid. Case 2: a 54-year-old previously healthy female with severe COVID-19 pneumonia developed thrombotic DIC, characterised by significant thrombocytopenia (platelets 65 × 109/L, nadir 40 × 109/L), multi-organ injury, and lower extremity venous thrombosis. She was successfully treated with low-molecular-weight heparin.ConclusionCOVID-19-associated DIC spans two phenotypes—thrombotic (platelet consumption, requiring anticoagulation) and haemorrhagic (fibrinogen consumption with hyperfibrinolysis, requiring antifibrinolytics)—validating the 2025 ISTH classification and highlighting the need for phenotype-specific therapy guided by serial coagulation monitoring.