1. Ashlesha Kaushik, MD* 2. Carol Pineda, MD* 3. Helen Kest, MD, MPH, CPH† 1. *Department of Pediatrics, St Joseph's Children's Hospital, Patterson, NJ. 2. †Division of Pediatric Infectious Disease, Department of Pediatrics, St. Joseph's Children's Hospital, Patterson, NJ. After completing this article, readers should be able to: 1. Describe the epidemiology and clinical spectrum of dengue viral infections. 2. Recognize when to consider dengue in the differential diagnosis of acute fever. 3. Discuss the diagnosis and management of this common tropical illness. 4. Identify other diseases that can mimic dengue viral infections. A 17-year-old Hispanic girl presents with a 5-day history of temperature of 39.4°C to 40.5°C and a 4-day history of severe bifrontal and intermittent headaches. She also has a 3-day history of malaise, generalized body aches, and mild epigastric pain. On the day of admission, she develops a dark reddish-purple, nonpruritic, and nonblanching rash over her arms and thighs and is brought to the emergency department. There is no cough, sore throat, vomiting, or diarrhea. She denies illicit drug use, tick exposure, sexual activity, or allergies. On physical examination, the girl appears alert, oriented, and in no acute distress. Her temperature is 38.5°C, heart rate is 119 beats/min, respiratory rate is 18 breaths/min, and blood pressure is 130/68 mm Hg (90th to 95th percentile). Capillary refill time is less than 2 seconds. A petechial rash is present over her arms and anterior thighs. She has mild epigastric tenderness, with no rebound tenderness, guarding, hepatosplenomegaly, or masses. Tourniquet test is positive. Kernig and Brudzinski signs are negative. The remainder of the physical examination findings are normal. Her white blood cell count is 3.5×103/mcL (3.5×10 9/L) with 59% neutrophils, 33% lymphocytes, 6% monocytes, and 1% eosinophils; hemoglobin is 13.4 g/dL (134 g/L); hematocrit is 39.6% (0.396); platelet count is 126×103/mcL (126×10 9/L); and erythrocyte sedimentation …