2025 ICD-10-CM Diagnosis Code B26.2

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Clinical Information

• Measles-Mumps-Rubella Vaccine

  a combined vaccine used to prevent measles; mumps; and rubella.

• Mumps

  an acute infectious disease caused by rubulavirus, spread by direct contact, airborne droplet nuclei, fomites contaminated by infectious saliva, and perhaps urine, and usually seen in children under the age of 15, although adults may also be affected. (from dorland, 28th ed)

• Mumps Vaccine

  vaccines used to prevent infection by mumps virus. best known is the live attenuated virus vaccine of chick embryo origin, used for routine immunization of children and for immunization of adolescents and adults who have not had mumps or been immunized with live mumps vaccine. children are usually immunized with measles-mumps-rubella combination vaccine.

• Mumps virus

  the type species of rubulavirus that causes an acute infectious disease in humans, affecting mainly children. transmission occurs by droplet infection.

• Viral Fusion Proteins

  proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. they promote cell membrane fusion and thereby may function in the uptake of the virus by cells.

• Rubulavirus

  a genus of the family paramyxoviridae (subfamily paramyxovirinae) where all the species have hemagglutinin and neuraminidase activities but lack a c protein. mumps virus is the type species.

Convert B26.2 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Patient Education

Encephalitis

What is encephalitis?

Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke, or even death.

What causes encephalitis?

There are different types of encephalitis, based on what the cause is. The two main types are infectious encephalitis and autoimmune encephalitis.

Infectious encephalitis is usually caused by a virus. In fact, viruses are the most common cause of encephalitis. Some of the different viruses that cause it include:

• Herpes viruses, including herpes simplex (HSV), the Epstein-Barr virus (which causes infectious mononucleosis) and the varicella-zoster virus (which causes chickenpox).
• Viruses you can get if you are bitten by an infected tick, such as tick-borne encephalitis (TBE virus) and Powassan virus.
• Viruses you can get if you are bitten by an infected mosquito, such as eastern equine encephalitis virus, West Nile virus, and La Crosse virus.
• Enteroviruses, which are a common group of viruses that mostly cause mild illness or respiratory infection. These infections usually happen in the summer and fall.

Bacteria, fungi, and parasites can also cause infectious encephalitis. But this is not common.

Autoimmune encephalitis happens when your immune system mistakenly attacks healthy brain cells. It can be triggered by conditions such as certain cancers, benign tumors, and infections. Sometimes the cause is not known.

Who is more likely to get encephalitis?

Anyone can get encephalitis, but you are more likely to get it if you:

• Have a weakened immune system, for example from having HIV or taking certain medicines. These could include medicines taken after an organ transplant, certain chemotherapy medicines, and specialized treatments for certain autoimmune diseases.
• Are a young child or older adult.
• Live in areas where there are ticks and mosquitoes that carry viruses that can cause encephalitis.

What are the symptoms of encephalitis?

The symptoms of encephalitis can vary a lot, depending on how severe it is. Many people do not have any symptoms. Others may have mild flu-like symptoms such as fever, fatigue, headache, or body aches. If encephalitis becomes more serious, it can cause:

• Severe headache
• Stiff neck
• Vomiting
• Seizures
• Behavior changes
• Drowsiness
• Muscle weakness
• Partial paralysis in your arms and legs
• Coma

Encephalitis can be dangerous in infants. Their symptoms may include:

• Fever
• Lethargy (weakness or drowsiness)
• Poor feeding
• Vomiting
• Body stiffness
• Unusual irritability or crying
• A full or bulging fontanel (the soft spot on the top of the head)

If you or your child is having symptoms of encephalitis, it's important to get medical care right away.

How is encephalitis diagnosed?

To find out if you have encephalitis, your health care provider:

• Will do a physical exam
• Will take your medical history, which includes asking about your symptoms
• May do a neurologic exam
• May order imaging tests, such as a brain CT scan or MRI
• May order an EEG (electroencephalography), which use small electric sensors to measure your brain activity
• May order blood and cerebrospinal fluid (CSF) tests

What are the treatments for encephalitis?

Most people with encephalitis will need treatment in the hospital. Depending on the cause, treatments may include antiviral medicines, antibiotics, corticosteroids, and other medicines.

For some types of encephalitis, there is no medicine to treat it. But rest, nutrition, and fluids can help your body fight the infection and relieve symptoms.

Some people may need physical, speech, and occupational therapy once the illness is under control.

Can encephalitis be prevented?

There are steps you can take to help prevent encephalitis that is caused by infections:

• Use good hygiene, including washing your hands often with soap and water.
• Don't share food, drinks, utensils, and glasses with other people.
• Get vaccines for viruses that can cause encephalitis.
• Avoid mosquito and tick bites, for example by:
  • Wearing insect repellent with DEET or another U.S. Environmental Protection Agency (EPA)-registered insect repellent. Make sure to follow the instructions for using the repellant.
  • Wearing clothes that cover your arms, legs and feet.
  • Treating your clothing and gear with products containing 0.5% permethrin before you go in grassy or woody areas.

NIH: National Institute of Neurological Disorders and Stroke

Mumps

Mumps is an illness caused by the mumps virus. It starts with:

• Fever
• Headache
• Muscle aches
• Tiredness
• Loss of appetite

After that, the salivary glands under the ears or jaw become swollen and tender. The swelling can be on one or both sides of the face. Symptoms last 7 to 10 days. Serious complications are rare.

You can catch mumps by being with another person who has it. There is no treatment for mumps, but the measles-mumps-rubella (MMR) vaccine can prevent it.

Before the routine vaccination program in the United States, mumps was a common illness in infants, children and young adults. Now it is a rare disease in the U.S.

Centers for Disease Control and Prevention

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.