A 4-year-old boy is brought to the emergency department by his parents for evaluation of a fever and headache. Two days ago, the boy began to have low-grade fever, cough, and congestion. Last night, his fever became higher, and he became fussy, more difficult to console, and less active. He slept poorly and woke up with a headache unrelieved with over the counter pain medications. The patient vomited twice prior to arrival. He has no medical conditions but has not received regular health maintenance or vaccinations. Temperature is 39.4 C (102.9 F), pulse is 110/min, and respirations are 20/min. Physical examination shows an irritable child. Pupils are equal and reactive; funduscopic examination is limited by photophobia. The oropharynx is erythematous. Nuchal rigidity is present and bilateral lower extremities flex when the neck is flexed. The remainder of the physical examination is normal. Cerebrospinal fluid results are shown below: Which of the following pathogens is most likely responsible for this patient's presentation?

Question

A 4-year-old boy is brought to the emergency department by his parents for evaluation of a fever and headache.  Two days ago, the boy began to have low-grade fever, cough, and congestion.  Last night, his fever became higher, and he became fussy, more difficult to console, and less active.  He slept poorly and woke up with a headache unrelieved with over the counter pain medications.  The patient vomited twice prior to arrival.  He has no medical conditions but has not received regular health maintenance or vaccinations.  Temperature is 39.4 C (102.9 F), pulse is 110/min, and respirations are 20/min.  Physical examination shows an irritable child.  Pupils are equal and reactive; funduscopic examination is limited by photophobia.  The oropharynx is erythematous.  Nuchal rigidity is present and bilateral lower extremities flex when the neck is flexed.  The remainder of the physical examination is normal.  Cerebrospinal fluid results are shown below:  Which of the following pathogens is most likely responsible for this patient's presentation?

Quizplus · Accepted Answer

11ec25c8_d6c5_8bb0_bc81_31fedab8aa6c_MD0003_00 This patient's cerebrospinal fluid (CSF) results are consistent with viral meningitis, or inflammation of the leptomeninges from a viral infection. The majority of cases are caused by enteroviruses, such as group B coxsackievirus. These viruses are spread by fecal-oral transmission and most commonly affect infants and young children. Viral meningitis can present with a viral prodrome (eg, upper respiratory symptoms) prior to the onset of high fever, headache, and nuchal rigidity. A positive Brudzinski sign may be elicited, but focal neurologic deficits are not usually seen. Brudzinski sign CSF analysis shows mild pleocytosis (elevated white blood cell count) with lymphocytic predominance (although neutrophils sometimes predominate early in the disease course). Normal to slightly elevated protein and normal glucose levels are typical. Viral PCR helps identify the pathogen, as CSF Gram stain and bacterial culture do not show organisms. Treatment is supportive (eg, antipyretics, pain control), and symptoms typically self-resolve within 1-2 weeks. (Choice A) Cryptococcal meningitis presents in immunosuppressed patients with a mildly elevated white blood cell count with lymphocyte predominance; however, protein is high and glucose is low. In addition, the presentation tends to be subacute (2-4 weeks) rather than acute. (Choice C) Tuberculous meningitis also presents with a mild CSF pleocytosis with lymphocyte predominance and elevated protein. However, CSF glucose is usually <45 mg/dL, and the presentation is typically subacute over the course of weeks. (Choices D and E) Meningitis caused by Neisseria meningitidis or Streptococcus pneumoniae has a similar presentation to this child, and unimmunized patients are at increased risk of contracting this disease. However, CSF results reveal dramatic pleocytosis with neutrophil predominance, increased protein, and a very low glucose. (Choice F) Neurosyphilis is due to a Treponema pallidum CNS infection. CSF findings include pleocytosis with lymphocytic predominance, elevated protein, and low glucose. Educational objective: The most common causes of viral meningitis are enteroviruses, such as group B coxsackievirus. Cerebrospinal fluid analysis shows mild pleocytosis with lymphocytic predominance, normal to slightly elevated protein, and normal glucose. References: Prediction of bacterial meningitis based on cerebrospinal fluid pleocytosis in children. (http://www.ncbi.nlm.nih.gov/pubmed/23602468) Trends in the management of viral meningitis at United States children's hospitals. (http://www.ncbi.nlm.nih.gov/pubmed/23530164)

A 4-Year-Old Boy Is Brought to the Emergency Department by His