A 9-year-old boy is brought to the physician for a 3-day history of fever, fatigue, and cough. His family immigrated to the United States from China four years ago. Temperature is 101 F. Laboratory studies show:
Hemoglobin 14.5 g/dL
Platelets 250,000/μL
WBCs 40,000/μL (80% lymphocytes)
Glucose 68 mg/dL (NR 72-99)
Which of the following is the most likely diagnosis?
Acute lymphoblastic leukemia
Croup
Diphtheria
Epiglottitis
Pertussis
