Spontaneous widespread muscle hematoma complicated by pyomyositis in a case of dengue hemorrhagic fever: a case report from Nepal.

Introduction and importance: Most dengue infections are asymptomatic, and some of them develop haemorrhagic manifestations with or without shock. However, dengue can sometimes present with very rare complications like pyomyositis. Case presentation: A healthy 27-year-old male, presented with a 2-day fever, confirmed to be dengue through a positive non-structural protein 1 test. Despite initial symptomatic management, his condition worsened and he was hospitalized. Leucocyte and platelet counts dropped to the lowest value on the seventh day of illness, followed by the gradual development of chest pain, persistent fever, and severe limb pain. Radiographic evaluation revealed pleural effusion, and multiple intramuscular haematomas complicated by pyomyositis. Pleural effusion resolved on its own. Pyomyositis resolved with 6 weeks of appropriate antibiotics and aspiration of pus. Clinical discussion: Dengue infection, caused by a dengue virus transmitted through Aedes mosquitoes, is a significant public health concern in many parts of the world. Dengue haemorrhagic fever is a severe form of dengue infection characterized by vascular leakage, thrombocytopenia, and bleeding manifestations. Although musculoskeletal manifestations are common in dengue fever, the occurrence of multiple muscle haematomas and pyomyositis as complications of Dengue haemorrhagic fever is rare. Drainage or aspiration of pus combined with the antibiotics according to the pus culture and sensitivity report is the management strategy. Conclusion: Prolonged fever with severe musculoskeletal pain and focal tenderness on examination in a dengue patient, warrant radiographic testing (ultrasonography or MRI) considering the differentials of haematoma, myositis, or pyomyositis.