Diagnostic accuracy of clinical symptoms and signs in children with meningitis

Background: The diagnostic accuracy of the classic symptoms and signs of meningitis in infants and children has not been established. Methods: All children aged 2 months to 16 years with clinically suspected meningitis were eligible for this prospective cohort study at 2 large medical centers between February 2006 and October 2007. Exclusion criteria were severe chronic disease, severe immune deficiency, or idiopathic intracranial hypertension. The emergency department physician obtained information on clinical symptoms and signs and cerebrospinal fluid analysis. Meningitis was defined as white blood cell count of 6 or higher per microliter of cerebrospinal fluid. Results: A total of 108 patients with suspected meningitis were enrolled. Meningitis was diagnosed in 58 patients (53.7%; 6 bacterial and 52 aseptic). Sensitivity and specificity were 76% and 53% for headache (among the verbal patients) and 71% and 62% for vomiting, respectively. Photophobia was highly specific (88%) but had low sensitivity (28%). Clinical examination revealed nuchal rigidity (in patients without open fontanel) in 32 (65%) of the patients with meningitis and in 10 (33%) of the patients without meningitis. Brudzinski and Kernig signs were present in 51% and 27% of the patients with meningitis, respectively, and had relatively high positive predictive values (81% and 77%, respectively). Bulging fontanel in patients with open fontanel was present in 50% of the patients with meningitis but had a positive predictive value of only 38%. Conclusions: Classic clinical diagnostic signs have limited value in establishing the diagnosis of meningitis in children and should not be the sole determinants for referral to further diagnostic testing and lumbar puncture.