Objective Children with viral meningitis may present with symptoms similar to those of Lyme meningitis. Current technology for reporting viral culture or Lyme serology often precludes a rapid diagnosis in the emergency department setting. We report our experience with clinical and laboratory predictors for the differentiation of viral and Lyme meningitis.
Methods Children aged 2–18 years presenting to a single paediatric emergency department in a Lyme-endemic region during the months of May to October over three consecutive years were prospectively enrolled when the attending physician had a suspicion of meningitis. Historical and physical examination findings were documented. Standards for laboratory evaluation of such patients included cerebrospinal fluid studies (cell count, Gram stain, bacterial culture, total protein, glucose) and peripheral Lyme titres/serology. Further diagnostic evaluation was at the discretion of the attending physician. The study received approval from the Institutional Review Board. Statistical analysis was performed using SPSS 11.5 for Windows (SPSS Inc, Chicago, Illinois, USA).
Results A total of 80 patients was enrolled. Of these, 44 had viral meningitis (55%), 12 had Lyme meningitis (15%) and 24 did not have aseptic meningitis (30%). Only the absence of cranial nerve palsy and the absence of the erythema chronicum migrans rash predicted viral meningitis. Other factors including headache, photophobia, cerebrospinal fluid lymphocyte and monocyte predominance were not helpful in predicting viral meningitis.
Conclusions Clinical and rapidly available laboratory data often fail to identify viral meningitis in a Lyme endemic area. The absence of the erythema chronicum migrans rash and cranial nerve palsy may support the diagnosis of viral meningitis.