Recurrent Meningitis

Recurrent viral meningitis is most often due to

• Herpes simplex virus type 2 (HSV-2; called Mollaret meningitis)

Typically when HSV-2 is the cause, patients have ≥ 3 episodes of fever, nuchal rigidity, and cerebrospinal fluid (CSF) lymphocytic pleocytosis; each episode lasts from 2 to 5 days, then resolves spontaneously. Approximately one-third of patients with HSV-2 meningitis report a history of viral meningitis (1). Patients can also have other neurologic deficits (eg, altered sensorium, seizures, cranial nerve palsies), indicating meningoencephalitis.

Acute bacterial meningitis may recur if it is acquired via a congenital or acquired defect at the skull base or in the spine and that defect is not corrected. If the defect is caused by an injury, meningitis may not develop until many years later.

If patients have recurrent bacterial meningitis, clinicians should thoroughly check for such defects. High-resolution CT can usually show defects in the skull. Clinicians should check the patient's lower back for a dimple or tuft of hair, which may indicate a defect in the spine (eg, spina bifida).

Rarely, recurrent bacterial meningitis (usually due to Streptococcus pneumoniae or Neisseria meningitidis) results from a deficiency in the complement system. Treatment is the same as that used in patients without complement deficits. Vaccination against S. pneumoniae and N. meningitidis (given according to Centers for Disease Control and Prevention [CDC] recommendations for patients with complement deficits) may reduce likelihood of infection.

Acute meningitis secondary to nonsteroidal anti-inflammatory drugs (NSAIDs) or other medications may recur when the causative medication is used again.

Meningitis caused by rupture of a brain cyst may also recur.

1. 1. Jakobsen A, Skov MT, Larsen L, et al; DASGIB Study Group. Herpes simplex virus 2 meningitis in adults: A prospective, nationwide, population-based cohort study. Clin Infectious Dis. 75(5):753–760, 2022. https://doi.org/10.1093/cid/ciab1071