Bacterial meningitis without clinical signs of meningeal irritation

A clinical diagnosis of meningitis in neonates is difficult because of the paucity of physical findings. In older infants and children, nuchal rigidity, Kernig's or Brudzinski's sign, or bulging fontanelles are sought. A review of 1,064 cases of bacterial meningitis beyond the neonatal period revealed that 16 (1.5%) patients had none of those meningeal signs during the entire hospitalization, despite CSF pleocytosis. Eight patients (50%) were 2 years old or older. Lumbar punctures were done because of unexplained fever, changes in behavior or mental status, seizures, or occurrence of skin petechiae in febrile patients. These patients frequently had moderate pleocytosis and all survived. The meningitis was caused by Neisseria meningitidis in seven patients, Haemophilus influenzae in six, Streptococcus pneumoniae in two, and Salmonella enteritidis in one patient. CSF should be examined in a patient of any age whenever meningitis is a consideration, even if patients lack meningeal signs.