Aseptic meningitis

Definition

Aseptic meningitis is an illness that appears similar to bacterial meningitis; however, bacteria do not grow in cultures of the fluid around the brain and spinal cord (cerebrospinal fluid).

See also:

• Meningitis
• Meningitis - cryptococcal
• Meningitis - gram-negative
• Meningitis - H. influenzae
• Meningitis - meningococcal
• Meningitis - pneumococcal
• Meningitis - staphylococcal
• Meningitis - tuberculous

Alternative Names

Sterile meningitis

Causes, incidence, and risk factors

There are many causes of aseptic meningitis, including:

• Infections near the brain or spinal cord, such as epidural abscesses
• Fungi
• Mycobacteria
• Some cancers (cause a syndrome similar to meningitis)
• Some medications (such as antibiotics and over-the-counter anti-inflammatory medications)
• Tick-borne diseases (such as Lyme disease)
• Tuberculosis
• Viruses

About half of aseptic meningitis cases are caused by the coxsackie virus and echovirus, two members the enterovirus family. The rate of enteroviral infections increases in the summer and early fall. Enteroviruses are spread by hand-to-mouth contact and coughing. They also may be spread by contact with fecal matter.

Other viruses that cause this condition include:

• Chickenpox (varicella virus)
• Other enteroviruses
• Herpes viruses, both type 1 (herpes simplex or herpes labialis) and type 2 (genital herpes)
• HIV (especially acute HIV syndrome)
• Mumps
• Rabies virus
• West Nile virus

Risk factors for aseptic meningitis include:

• Being a health care worker
• Having a suppressed immune system
• Exposure to children in a day care setting
• Exposure to someone with a recent viral infection

Symptoms

• Abdominal pain
• Abnormal sensitivity to light (photophobia)
• Chills
• Confusion
• Drowsiness
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Headache
• Muscle pain
• Nausea and vomiting
• Rash
• Sore throat
• Stiff neck

Signs and tests

For any patient with meningitis, it is important to perform a lumbar puncture ("spinal tap"), in which a sample of spinal fluid (known as cerebrospinal fluid, or CSF) is taken for testing.

Tests may include:

• Bacterial cultures of spinal fluid
• Other cultures or special tests of spinal fluid
• White blood cell count
• White blood cell count in spinal fluid

Treatment

Treatment is needed for fungal or mycobacterial causes of aseptic meningitis. Herpesvirus or varicella (chicken pox) virus may be treated with antiviral medicines. Treatment for non-infectious causes consists of pain medications and management of complications, if they occur.

No specific treatment is available for enteroviral aseptic meningitis.

Expectations (prognosis)

Aseptic meningitis caused by a virus is usually a harmless disease. People usually recover fully 5 - 14 days after symptoms start.

Fatigue and light-headedness may last longer in some people.

Complications

An infection of the brain (encephalitis) may develop, though this is rare. The infection may last much longer in a person with a depressed immune system.

Calling your health care provider

Call your health care provider if you have symptoms of aseptic meningitis.

Prevention

To reduce the risk of developing an infection that can become meningitis:

• Get vaccinated (against mumps or chickenpox, for example)
• Practice good hand washing
• Practice other general good health measures

References

Swartz MN. Meningitis: bacterial, viral, and other. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsever; 2007: chap 437.