Recurrent meningitis is usually caused by bacteria, viruses, or noninfectious conditions.
(See also Overview of Meningitis Overview of Meningitis Meningitis is inflammation of the meninges and subarachnoid space. It may result from infections, other disorders, or reactions to drugs. Severity and acuity vary. Findings typically include... read more .)
Recurrent viral meningitis
Recurrent viral meningitis Viral Meningitis Viral meningitis tends to be less severe than acute bacterial meningitis. Findings include headache, fever, and nuchal rigidity. Diagnosis is by cerebrospinal fluid (CSF) analysis. Treatment... read more is most often due to
Herpes simplex virus type 2 Herpes Simplex Virus (HSV) Infections Herpes simplex viruses (human herpesviruses types 1 and 2) commonly cause recurrent infection affecting the skin, mouth, lips, eyes, and genitals. Common severe infections include encephalitis... read more (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. Patients can also have other neurologic deficits (eg, altered sensorium, seizures, cranial nerve palsies), indicating meningoencephalitis.
The cause is treated if possible. Mollaret meningitis is treated with acyclovir. Most patients recover fully.
Recurrent acute bacterial meningitis
Acute bacterial meningitis Acute Bacterial Meningitis Acute bacterial meningitis is rapidly progressive bacterial infection of the meninges and subarachnoid space. Findings typically include headache, fever, and nuchal rigidity. Diagnosis is by... read more 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 Spina Bifida Spina bifida is defective closure of the vertebral column. Although the cause is not known, low folate levels during pregnancy increase risk. Some children are asymptomatic, and others have... read more ).
Rarely, recurrent bacterial meningitis (usually due to Streptococcus pneumoniae or Neisseria meningitidis) results from a deficiency in the complement system Complement deficiencies and defects The complement system is an enzyme cascade that helps defend against infection. Many complement proteins occur in serum as inactive enzyme precursors (zymogens); others reside on cell surfaces... read more . 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.
Recurrent bacterial meningitis is treated with antibiotics and dexamethasone.
Other recurrent meningitides
Acute meningitis secondary to nonsteroidal anti-inflammatory drugs (NSAIDs) or other drugs may recur when the causative drug is used again.
Meningitis caused by rupture of a brain cyst may also recur.