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Validation of a clinical prediction rule to distinguish Lyme meningitis from aseptic meningitis

Keri A Cohn1, Amy D Thompson, Samir S Shah

  • 1Division of Emergency Medicine, Children's Hospital and Harvard Medical School, Boston 300 Longwood Ave, Boston, MA 02115, USA.

Pediatrics
|December 21, 2011
PubMed

Insights

The Rule of 7's accurately identifies children at low risk for Lyme meningitis, with only 2% of low-risk patients without a rash developing the condition. This suggests low-risk children can be managed as outpatients pending test results.

Area of Science:

  • Pediatric Infectious Diseases
  • Neurology
  • Clinical Prediction Rules

Background:

  • Lyme meningitis is a significant concern in children residing in endemic areas.
  • Accurate clinical prediction rules are crucial for timely diagnosis and management.
  • The Rule of 7's is a proposed clinical prediction rule for identifying low-risk children.

Purpose of the Study:

  • To evaluate the performance of the Rule of 7's in a multicenter cohort of pediatric patients.
  • To assess the rule's accuracy in classifying children with cerebrospinal fluid (CSF) pleocytosis.
  • To determine the utility of the Rule of 7's in guiding outpatient management.

Main Methods:

  • Retrospective cohort study involving children from three emergency departments in Lyme disease-endemic regions.
  • Inclusion criteria: CSF pleocytosis and available Lyme serology.
  • Lyme meningitis definition: Positive Lyme serology or erythema migrans (EM) rash.

Main Results:

  • Out of 423 children, 117 (28%) had Lyme meningitis.
  • The Rule of 7's identified 130 low-risk children; 5 (4%) had Lyme meningitis (sensitivity 96%, specificity 41%).
  • In children without EM, only 3 of 127 low-risk patients (2%) had Lyme meningitis.

Conclusions:

  • The Rule of 7's demonstrates high sensitivity for identifying children with Lyme meningitis.
  • Children classified as low-risk by the Rule of 7's have a low probability of having Lyme meningitis.
  • The Rule of 7's supports outpatient management for low-risk children while awaiting Lyme serology results.
Abstract

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