ToolsCalculators
Rule of 7s for Lyme Meningitis
Identifies children at low risk for Lyme meningitis among those with CSF pleocytosis.
Rule of 7s for Lyme Meningitis
Days of headache
CSF mononuclear cells
Cranial nerve palsy (7th or other)
Result0 points
Low risk for Lyme meningitis: outpatient management pending Lyme serology may be reasonable.
- Low risk
- 0 of 3 predictors
When to use
- Children in Lyme-endemic areas with CSF pleocytosis, to distinguish low-risk from possible Lyme meningitis.
Formula
One point each for: >=7 days of headache, >=70% CSF mononuclear cells, and presence of any cranial nerve palsy. A score of 0 (all three absent) defines low risk.
Pearls and pitfalls
- Low-risk classification supports deferring parenteral antibiotics and inpatient care while awaiting serology.