Case 2: Fever and Myalgia in a 16-Year-old Boy

1. Emily Ann Fretz, MD* 2. Aaron Miller, MD, MSPH* 3. Marta Ania King, MD, MEd* 1. *Saint Louis University School of Medicine and Cardinal Glennon Children’s Medical Center, St Louis, MO A 16-year-old previously healthy boy presents to the emergency department in the summer with 6 days of high fevers, myalgias, arthralgias, anorexia, and fatigue and 1 day of headache and emesis. The fevers have occurred daily, with temperatures as high as 104.5°F (40.3°C), and are associated with chills. The patient has complained of diffuse symmetrical myalgias and arthralgias without joint warmth, edema, or redness. Although the patient experienced transient improvement with acetaminophen and ibuprofen, symptoms have overall progressively worsened. The patient lives in a wooded area of Missouri and recalls many insect bites. Three weeks before presentation he was bitten by a tick, which he promptly removed. A month earlier the patient returned from a 2-week trip across the Midwest during which he hiked, camped, swam in freshwater rivers and lakes, and was exposed to bats while caving. The family has a pet cat and dog, but he has no known scratches, bites, or exposures to other animals. He had no sick contacts. On private questioning he denied sexual activity and drug use. Family history is negative. Vital signs are significant for a temperature of 103.5°F (39.7°C), pulse of 138 beats/min, and blood pressure of 140/60 mm Hg. Physical examination shows an ill-appearing teenager with moderate dehydration, bilateral nonexudative conjunctivitis, and excoriated papules over the calves, but no rashes, no lymphadenopathy, no meningeal signs, and a normal neurologic examination. The diagnostic evaluation is significant for …