Fulminant bilateral upper limb thrombophlebitis following traumatic brain injury in a patient with chronic substance use: A fatal case of trauma-associated immunothrombosis.

Background: Bilateral upper limb superficial thrombophlebitis is rare in trauma patients and typically indicates systemic thromboinflammatory activation rather than localized vascular injury. Trauma-associated immunothrombosis is increasingly recognized as distinct from classical disseminated intravascular coagulation (DIC). Case presentation: A 35-year-old male presented with severe traumatic brain injury (TBI) following an unwitnessed fall. On hospital day six, he developed progressive discoloration of the left hand, rapidly involving the right upper limb. Doppler ultrasonography confirmed bilateral cephalic and basilic vein thrombosis without deep venous involvement. Platelet count declined from 40,000/μL on day seven to 10,000/μL on day eight, while prothrombin time and INR remained normal and fibrinogen levels were elevated. Admission chest radiograph was normal; however, repeat imaging on day eight demonstrated diffuse bilateral alveolar opacities. HRCT revealed extensive multilobar consolidation with surrounding ground-glass opacities, radiologically suggestive of severe diffuse alveolar injury with features compatible with alveolar hemorrhage. CTPA showed no large central pulmonary embolism. Repeat CT brain demonstrated stable extradural hematoma with resolution of subarachnoid hemorrhage and partial resolution of subdural hematoma. Anticoagulation was withheld due to intracranial hemorrhage and profound thrombocytopenia. The patient developed refractory hypoxemic respiratory failure and died on hospital day eight. Conclusion: This case highlights a rare and catastrophic systemic thromboinflammatory complication following TBI. Early recognition and multidisciplinary management are essential in similar rapidly progressive cases.