What Is Aseptic Meningitis?

Aseptic meningitis is inflammation of the meninges, a trio of membranes that cushion your brain and spinal cord, without a known bacterial cause. This type is more common and less severe than bacterial meningitis.

You might develop symptoms like a stiff neck, headache, and sensitivity to light. Several contagious pathogens, such as bacteria and viruses, may cause meningitis. Still, about two-thirds of aseptic meningitis do not have a known cause. Treatment depends on the cause but may include prophylactic antibiotics in case a bacterium is the culprit.

Aseptic meningitis affects about eight out of every 100,000 adults per year. Read on to learn what aseptic meningitis is, including symptoms, causes, treatment, and more.

Aseptic Meningitis Symptoms

Aseptic meningitis causes similar symptoms to bacterial meningitis. In contrast, aseptic meningitis is usually not life-threatening. Children, adolescents, and young adults often recover without complications, Paul Auwaerter, MD, clinical director of the division of infectious diseases at Johns Hopkins Medicine, told Health.

Aseptic meningitis symptoms include:

• A stiff neck
• Altered mental status (e.g., confusion)
• Fever (in children)
• Headache
• Malaise, or a general ill feeling
• Nausea and vomiting
• Rash (in children)
• Sensitivity to light
• Weakness

What Causes Aseptic Meningitis?

There are contagious and non-contagious causes of aseptic meningitis. Contagious viruses are the most common cause of aseptic meningitis. Non-polio enteroviruses, which usually cause colds, cause most viral meningitis cases in the U.S.

Other viruses that may cause aseptic meningitis include:

• Arboviruses (e.g., West Nile virus)
• Flu viruses
• Herpes simplex virus (HSV)
• Human immunodeficiency virus (HIV)
• Lymphocytic choriomeningitis virus
• Measles and mumps viruses
• Varicella-zoster virus, which causes chickenpox and shingles

Bacteria, fungi, and parasites cause aseptic meningitis less commonly than viruses. Fungal meningitis might occur if a fungal infection spreads to the brain or spinal cord.

Risk Factors

Anyone can develop aseptic meningitis. Still, some non-contagious factors might increase your risk, such as:

• Certain health conditions: These include illnesses that affect the meninges, such as lupus and Sjögren's syndrome, both of which are autoimmune disorders.
• Insect-borne infections: Lyme disease and other tick- or mosquito-borne infections might increase your risk. A healthcare provider might ask about your recent travels or time spent outdoors, Marie Grill, MD, a neurologist at the Mayo Clinic in Phoenix, told Health.
• Medications: Prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may cause aseptic meningitis. Other medications include antibiotics, immunosuppressants, and anti-epileptic drugs.
• Vaccines: These include rubella, varicella, rabies, pertussis, and flu vaccines. Keep in mind that researchers note routine vaccines rarely, if ever, cause meningitis. The benefits of vaccines greatly outweigh the risks.
• Weak immune system: This increases your risk of fungal aseptic meningitis, Claire Wright, health insights, policy and disease information manager of the Meningitis Research Foundation, told Health.
  

How Is Aseptic Meningitis Diagnosed?

A healthcare provider will typically start by taking your health history and asking questions about recent travel or possible exposures. A physical exam helps assess your symptoms that might signal meningitis. Healthcare providers usually use diagnostic tests to rule out and confirm the cause of meningitis. In contrast, as many as two-thirds of aseptic meningitis causes do not have a known cause.

Diagnostic tests that may help figure out the cause of aseptic meningitis include:

• Imaging tests: These include CT scans and MRIs, which look for inflammation and swelling of your brain and spinal cord.
• Lab tests: Your glucose and white blood cell levels might offer clues about whether you have aseptic meningitis and, if so, what is causing it, said Dr. Grill. A healthcare provider might use antibody tests to check for different viruses.
• Lumbar puncture (spinal tap): A healthcare provider will draw a small amount of cerebrospinal fluid (CSF) from your lower back and test it for aseptic meningitis.

Treatments for Aseptic Meningitis

Aseptic meningitis treatments are not always necessary, but it depends on the cause. Healthcare providers often prescribe prophylactic antibiotics in case your tests show that you have bacterial meningitis.

Treatment for drug-induced aseptic meningitis is straightforward: stop taking that medication. Symptoms usually clear up within 24–48 hours. Supportive care can keep you comfortable as you recover in the meantime.

Bacterial

Treating bacterial meningitis begins right away and typically involves intravenous (IV) antibiotics. A healthcare provider may prescribe steroids to help lower your risk of serious complications.

"With bacterial meningitis, if the bacteria enter the bloodstream, they can replicate so rapidly, and they produce toxins that, if you're not given antibiotics very quickly, can [cause you to] rapidly deteriorate, and it can become fatal," said Wright.

Fungal

A healthcare provider typically relies on a long course of high-dose antifungal medications to wipe out the infection. How long you need treatment depends on your immune system and the fungus that's causing the infection.

Viral

Most people recover from viral meningitis within 10 days or less without treatment. Meningitis from the West Nile virus can be severe and cause lingering fatigue and weakness for weeks or months.

"In terms of viral meningitis, there's no sort of set of treatments," said Wright. "It would just be things like bed rest, taking it easy, and just waiting for the symptoms to subside."

How To Prevent Aseptic Meningitis

You can take steps to prevent contracting and spreading contagious causes of aseptic meningitis, including bacteria and viruses. Prevention includes isolating yourself from others at home if you are sick and washing your hands regularly.

It's essential to stay up-to-date with vaccines, including ones that protect you from:

• Chickenpox
• Flu
• Measles
• Mumps
• Polio
• Rubella
  

When To Contact a Healthcare Provider

Contact a healthcare provider right away if you develop meningitis symptoms, such as a stiff neck, headache, and sensitivity to light. Early diagnosis and treatment improve your chances of a full recovery. Meningitis may be fatal if untreated.

Other complications that might occur with meningitis include:

• Brain and neurologic damage
• Hearing loss
• Hydrocephalus, or a build-up of fluid in your skull, resulting in brain swelling
• Seizures
• Subdural effusion, or a build-up of fluid between your brain and skull
  

A Quick Review

Aseptic meningitis is more common and less severe than bacterial meningitis. You might develop similar symptoms, such as a stiff neck, headache, and sensitivity to light. Most times, healthcare providers cannot determine a specific cause.

It's important to treat aseptic meningitis with prophylactic antibiotics in case a bacterium is the cause. Bacterial meningitis might cause complications, including death, if untreated. See a healthcare provider right away if you develop meningitis symptoms.