Meningitis

About Meningitis

Meningitis is inflammation of the meninges, the membranes surrounding the brain and spinal cord, usually from infection. Bacterial meningitis is a medical emergency; anyone with suspected meningitis, or fever with a rash that does not fade under pressure, needs emergency help via the local emergency number. Common organisms include Streptococcus pneumoniae pneumococcus, Neisseria meningitidis meningococcus, and Haemophilus influenzae type b Hib. Viral meningitis is more common but usually less severe, often caused by enteroviruses, HSV, and VZV. The classic triad of bacterial meningitis is fever, neck stiffness nuchal rigidity, and altered mental status, though not all patients have all three. Other symptoms include severe headache, photophobia, nausea, vomiting, seizures, and the characteristic meningococcal rash petechial or purpuric that does not blanch with pressure. The rash indicates meningococcal septicemia and is a medical emergency. In infants, symptoms may include poor feeding, irritability, bulging fontanelle, and hypotonia. Diagnosis requires lumbar puncture CSF analysis showing elevated white blood cells, protein, and in bacterial meningitis, low glucose. CT scanning is performed before LP when there are signs of increased intracranial pressure or focal neurological deficits. In hospital, intravenous antibiotics such as ceftriaxone, sometimes with vancomycin or ampicillin, are started urgently, often before LP results are available. Dexamethasone reduces inflammation and improves outcomes in pneumococcal meningitis. Vaccines against pneumococcus, meningococcus, and Hib have dramatically reduced bacterial meningitis incidence.