Test your knowledge

An 11-month-old boy with a two-day history of irritability and lethargy is brought to the emergency department by his mother.

She reports that he has vomited four times that day and has had fewer wet nappies than usual.

He is up to date with his vaccinations.

On examination, he is febrile, and a slight bulging of his anterior fontanel and neck stiffness are noted.

Laboratory tests demonstrate a serum glucose of 75 mg/dL. Blood cultures and a lumbar puncture are performed. Analysis of the cerebrospinal fluid (CSF) reveals a predominance of neutrophils. Which additional CSF finding is most likely?

  • Glucose of 50 mg/dL
  • Protein of 98 mg/dL
  • Glucose of 18 mg/dL
  • White blood cell count of 90/microL

The answer is under the image.

Image credit: @IBercholcMD.