Herpes meningitis is a type of viral meningitis that results from infection with a herpes virus. It causes swelling in areas of the head, such as the membranes surrounding the brain and spinal cord.

Meningitis is the medical term for inflammation of the meninges. Viral meningitis is meningitis that occurs as a result of a viral infection.

The meninges are a collection of membranes that encapsulate and protect the brain and spinal cord. They consist of three layers:

  • The pia mater: The delicate inner layer.
  • The arachnoid: The fluid-filled, web-like layer that provides cushioning.
  • The dura, or dura mater: The tough outer layer that provides protection.

This article describes herpes meningitis (HM), including the symptoms, causes, diagnosis, treatment, and prevention. It also looks at the way in which herpes viruses transmit from person to person.

HM is meningitis resulting from infection with a herpes virus, such as the herpes simplex virus (HSV). According to an older review from 2008, HSV is the second leading cause of viral meningitis in developed countries.

Three types of herpes viruses can cause HM:

  • Herpes simplex virus type 1 (HSV-1): This type can cause sores on the mouth or genitals, but it most commonly affects the mouth.
  • Herpes simplex virus 2 (HSV-2): This type can also cause sores on the mouth, but they are more likely to appear on the genitals.
  • Varicella-zoster virus (VZV): This type can cause chickenpox and shingles.

A 2008 review outlines one study of 144 adults, in which HSV-1, HSV-2, and VZV were responsible for 4%, 31%, and 11% of viral meningitis cases, respectively.

HSV viruses can also cause Mollaret’s meningitis, also called recurrent lymphocytic meningitis. This recurring form of meningitis involves sporadic periods of meningitis lasting 2–7 days.

The viruses that can cause viral meningitis can transmit from one person to another via coughs and sneezes, or through contact with surfaces contaminated with the virus.

Herpes viruses, in particular, can spread through kissing or sexual contact. These viruses stay in a person’s body for life, and triggers cause periodic active outbreaks.

Can it pass to a baby?

The virus can pass from a person with an HSV infection to a baby during childbirth. A baby who has contracted HSV will often experience symptoms by the end of their first week of life.

Possible signs of HSV infection in babies include:

  • irritability
  • blisters
  • yellowing of the skin and eyes, called jaundice
  • labored or intermittent breathing
  • rapid breathing
  • blue coloration of the skin
  • bleeding easily

Mild cases of HM may cause flu-like symptoms. A person may experience a persistent headache along with one or more of the following:

People with mild cases of viral HM typically recover within 7–10 days.

A doctor will start the diagnostic process for HM by asking about the person’s symptoms and medical history. If the doctor suspects viral meningitis, they may order the following tests to confirm or identify the viral infection:

Most mild cases of viral meningitis resolve completely in 7–10 days without the need for medical treatment. However, a doctor may prescribe antiviral medications for viral meningitis due to HSV or influenza.

People who develop severe viral meningitis may require treatment in a hospital setting.

Some cases of HM can progress to become herpes meningoencephalitis. This severe neurological condition involves swelling of both the meninges and the brain.

The standard treatment approach for herpes meningoencephalitis is a combination of antiviral drugs and medications to reduce brain swelling and prevent seizures. Most people respond to treatment within 1–2 days and recover fully within a month or so. However, those with severe cases are at risk of long-term brain damage.

Without treatment, herpes meningoencephalitis can lead to serious complications, and it can even be fatal.

The most effective way to prevent HM is to take steps to avoid infection with HSV. These steps include:

  • avoiding kissing someone with a cold sore
  • using condoms to reduce exposure to genital sores
  • limiting sexual partners to those who have tested negative for HSV
  • abstaining from sexual contact with a partner who has an active outbreak of HSV
  • washing the hands thoroughly and regularly
  • cleaning and disinfecting surfaces that may be contaminated with viruses

In general, early treatment for HM leads to the best outcomes. A person should contact a doctor if they or a child in their care experiences any of the following symptoms of viral meningitis:

  • persistent headache
  • fever
  • neck stiffness
  • sensitivity to light
  • nausea and vomiting
  • sleepiness or difficulty waking
  • trouble breathing
  • abnormal bleeding

If the person experiencing symptoms has a history of HSV infection, they should make the doctor aware of this fact as soon as possible. Doing so can speed up the diagnostic process, allowing the person to receive treatment sooner.

Herpes meningitis is a type of viral meningitis resulting from infection with a herpes virus. Three types of herpes virus can cause HM: herpes simplex virus 1, herpes simplex virus 2, and varicella-zoster virus.

Meningitis involves swelling of the meninges, which are the membranes that encapsulate the brain and spinal cord. This swelling can cause a persistent headache along with other symptoms, such as neck stiffness, light sensitivity, and fever.

Most cases of HM are mild and fully resolve without medical treatment within a week. People who experience severe cases of HM may require hospitalization. Some cases may progress to become meningoencephalitis, which is a severe neurological condition that requires immediate medical attention.