Fever of Unknown Origin With Normal Inflammatory Markers Due to Latent Pulmonary Embolism and Deep Vein Thrombosis: A Case Report

An 86-year-old woman who was hospitalized due to cerebral hemorrhage developed an intermittent fever of up to 39.3°C. A computed tomography angiography of the chest with venous runoff to the legs showed pulmonary embolism (PE) and deep vein thrombosis (DVT) of the legs. Intravenous heparin rapidly reduced the fever, indicating that these thrombi were the primary cause of her fever. During her course, white blood cell count and serum C-reactive protein levels were always within normal limits. This case suggested that latent PE and DVT can be a cause of intermittent fever with normal inflammatory markers.