Post-Dengue Deep Vein Thrombosis Complicated by Pulmonary Embolism: A Case Report

Dengue fever is commonly associated with bleeding complications, particularly in patients with thrombocytopenia. However, thrombotic events, such as venous thromboembolism, are rare and under-recognized manifestations, particularly during the recovery phase, posing diagnostic and therapeutic challenges. We report the case of a 25-year-old previously healthy male who presented with high-grade fever, myalgia, and headache and was diagnosed with dengue fever based on positive NS1 antigen testing. Dengue infection was confirmed by a positive NS1 antigen test performed on Day 3 of illness, consistent with early acute dengue infection. The diagnosis was further supported by the patient's clinical presentation, including high-grade fever, myalgia, and headache in the appropriate epidemiological context of a dengue-endemic region. During the recovery phase of the illness, he developed painful swelling of the right lower limb and progressive dyspnea. Investigations revealed markedly elevated D-dimer levels, right lower limb deep vein thrombosis on Doppler ultrasound, and bilateral pulmonary emboli with right ventricular strain on CT pulmonary angiography images. Although dengue-associated thrombosis has been reported in the setting of thrombocytopenia, as described by Ghatak et al., the present case demonstrates that thrombotic complications may also occur despite preserved platelet counts, highlighting the potential contribution of endothelial dysfunction and inflammatory activation. This case highlights the paradoxical coexistence of thrombosis and bleeding risk in dengue fever. To avoid potentially fatal thromboembolic complications in patients with dengue, early diagnosis, prompt anticoagulation, and a high index of suspicion are crucial.