2024 ICD-10-CM Diagnosis Code A86

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

• Acute encephalitis
• Acute encephalitis
• Acute necrotizing encephalitis
• Acute viral encephalitis
• Arenavirus encephalitis
• Arenavirus meningitis
• Chronic echovirus meningoencephalitis
• Chronic infectious disease of central nervous system
• Chronic infectious disease of central nervous system
• Chronic meningitis
• Chronic viral encephalitis
• Dementia associated with viral encephalitis
• Echovirus encephalitis
• Echovirus meningitis
• Enterovirus meningitis
• Epidemic encephalitis
• Infection caused by Lymphocytic choriomeningitis virus
• Infective ventriculitis
• Lymphocytic choriomeningitis
• Lymphocytic choriomeningitis virus encephalitis
• Meningoencephalitis caused by Lymphocytic choriomeningitis virus
• Meningoencephalitis caused by virus
• Meningoencephalitis caused by virus
• Primary encephalitis
• Primary viral encephalitis
• Ventriculitis of the brain
• Ventriculitis of the brain
• Viral encephalitis
• Viral ventriculitis

Clinical Information

• Arenaviruses, Old World

  one of two groups of viruses in the arenavirus genus and considered part of the old world complex. it includes lassa virus and lymphocytic choriomeningitis virus, although the latter has worldwide distribution now.

• Lymphocytic Choriomeningitis

  a form of meningitis caused by lymphocytic choriomeningitis virus. mice and other rodents serve as the natural hosts, and infection in humans usually occurs through inhalation or ingestion of infectious particles. clinical manifestations include an influenza-like syndrome followed by stiff neck, alterations of mentation, ataxia, and incontinence. maternal infections may result in fetal malformations and injury, including neonatal hydrocephalus, aqueductal stenosis, chorioretinitis, and microcephaly. (from joynt, clinical neurology, 1996, ch26, pp1-3)

• Lymphocytic choriomeningitis virus

  the type species of arenavirus, part of the old world arenaviruses (arenaviruses, old world), producing a silent infection in house and laboratory mice. in humans, infection with lcmv can be inapparent, or can present with an influenza-like illness, a benign aseptic meningitis, or a severe meningoencephalomyelitis. the virus can also infect monkeys, dogs, field mice, guinea pigs, and hamsters, the latter an epidemiologically important host.

• Cordonnier Grade 3 Viral Complication, Viral Encephalitis|Grade 3 Any Viral Encephalitis

  any viral encephalitis.

• Mosquito-Borne Viral Encephalitis

  viral encephalitis that is transmitted by mosquitos.

• Tick-Borne Viral Encephalitis

  viral encephalitis that is transmitted by ticks.

• Viral Encephalitis

  encephalitis resulting from viral infection.

• Epidemic Encephalitis

  a term that may be used to describe encephalitis characterized by sleepiness, which is likely due to a viral cause.

Convert A86 to ICD-9-CM

• ICD-9-CM Code: 049.9 - Viral encephalitis NOS
  Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education

Encephalitis

Encephalitis is an inflammation of the brain. Usually the cause is a viral infection, but bacteria can also cause it. It can be mild or severe. Most cases are mild. You may have flu-like symptoms. With a mild case, you may just need rest, plenty of fluids, and a pain reliever.

Severe cases need immediate treatment. Symptoms of severe cases include:

• Severe headache
• Sudden fever
• Drowsiness
• Vomiting
• Confusion
• Seizures

In babies, additional symptoms may include constant crying, poor feeding, body stiffness, and bulging in the soft spots of the skull.

Severe cases may require a stay in the hospital. Treatments include oral and intravenous (IV) medicines to reduce inflammation and treat infection. Patients with breathing difficulties may need artificial respiration. Some people may need physical, speech, and occupational therapy once the illness is under control.

NIH: National Institute of Neurological Disorders and Stroke

[Learn More in MedlinePlus]

Viral Infections

What are viruses?

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease. Some of the diseases that viruses can cause include the common cold, the flu, COVID-19, and HIV.

How are viruses spread?

Viruses can be spread in different ways:

• Through droplets and particles that are breathed out by someone who has the infection. You might breathe in the droplets or particles, or they could land on your mouth, nose, or eyes.
• By touching surfaces or objects that have the virus on them and then touching your mouth, nose, or eyes.
• From the pregnant parent to the baby during pregnancy.
• Through contaminated food or water.
• By being bitten by an infected insect or animal.
• Through sexual contact (usually vaginal, anal and oral sex) with someone who has the infection.

How do viruses cause disease?

Viruses are like hijackers. They invade living, normal cells. They then use those cells to multiply (make copies of themselves). This process is also called replication. The process can kill, damage, or change the infected cells. Sometimes this can make you sick. The symptoms can range from mild to very severe. Other times, your immune system may be able to fight it off and you may not have any symptoms.

Each different virus usually only infects one type of cell in your body. For example, hepatitis viruses affect the cells in the liver. HIV infects a certain type of immune system cell.

What are the treatments for viral infections?

For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. There are antiviral medicines to treat some viral infections. Antibiotics do not work for viral infections.

Can viral infections be prevented?

Vaccines can help prevent you from getting many viral diseases. You may be able to prevent some viral infections by:

• Proper hand washing.
• Paying attention to food safety.
• Cleaning surfaces that may be infected with germs.
• Avoiding contact with wild animals.
• Preventing insect bites by using insect repellent when you go outdoors. If you travel to an area that has a high risk of diseases from insect bites, also wear long pants, shirts, and socks.
• Practicing safe sex (using a condom every time you have anal, vaginal, or oral sex).
• Avoiding close contact with people who are sick.

[Learn More in MedlinePlus]

Code History

• FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
• FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
• FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
• FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
• FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
• FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
• FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
• FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
• FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.