Eosinophilic asthma (EA) is a type of severe asthma. It’s marked by high levels of white blood cells.

These cells, called eosinophils, are a natural part of your body’s immune system. They fight infections and attack invading bacteria. However, in people with EA, these white blood cells cause inflammation and swelling in the airways and respiratory system. The higher the levels of eosinophils in the blood, the more severe the symptoms of asthma can be.

EA is rare. It’s not clear how many people have this subtype of asthma, but researchers believe about 5 percent of all adults with asthma have EA.

It’s also difficult to treat and can impact quality of life. Recognizing the symptoms of this type of asthma can help you and your doctor look for effective treatment options that may reduce the risk of complications.

What are the symptoms?

Symptoms of EA can mimic many typical asthma symptoms. However, a few are more likely to occur in people with this subtype of asthma. These symptoms include:

Some of the symptoms of this type of asthma more closely resemble those of chronic pulmonary obstructive disorder (COPD). Working with your doctor to understand your symptoms and find the proper diagnosis can help you get treatment that is more successful.

How is it diagnosed?

If you’ve been diagnosed with asthma but don’t seem to respond well to treatment, your doctor may suspect you have a less common subtype of asthma. They’ll likely evaluate your condition and look for additional signs or symptoms that can direct them toward a diagnosis.

In the case of EA, the easiest step is to check your levels of white blood cells. For this, your doctor will collect blood, sputum, or saliva and send it to a lab. High levels of eosinophils can affirm your doctor’s suspected diagnosis.

In addition to the blood test, however, your doctor may conduct a physical exam. Certain physical symptoms, such as nasal polyps, can confirm the suspected diagnosis. The combination of the blood test and the physical exam may be enough for your doctor to diagnose you.

How is it treated and managed?

In the United States, 1 in 12 people has asthma. As doctors now recognize that asthma is more than one condition, they realize that the subtypes need specific treatments. Individual treatments for each subtype can help you achieve the best outcome for the condition.

Traditional asthma treatment involves inhaled corticosteroids and a rescue inhaler. However, people with EA don’t always respond well to inhaled corticosteroids. Higher doses may lose their impact too, requiring a switch to an entirely new treatment.

That’s why doctors aim to promptly manage the inflammation caused by EA and reduce the likelihood of future severe inflammation. If the inflammation can be managed, the symptoms and side effects of this type of asthma may be less severe.

The most common treatments for EA include the following.


Inhaled corticosteroids don’t work for everyone, so your doctor may prescribe the pill version. Corticosteroid pills have more side effects and complications than an inhaler, so be sure to talk about this with your doctor.

Fact-acting inhalers

Rescue inhalers are commonly prescribed for people with asthma. They can help people with this type of asthma, but they may lose their efficacy over time.

Leukotriene modifiers

Leukotrienes are compounds in your body that team up with eosinophils and cause inflammation. Leukotriene modifiers fight the inflammatory response these compounds cause in the body. Commonly prescribed medications in this category include montelukast (Singulair), zileuton (Zyflo), and zafirlukast (Accolate).

Biologic therapies

These medications work to block the chemicals in your body that cause inflammation and swelling. They are delivered by an injection or intravenous (IV) drip. Biologics prescribed for EA include omalizumab (Xolair) and mepolizumab (Nucala).

Complications of EA

EA can impact your quality of life if you don’t treat a flare-up swiftly and consistently. Over time, the inflammation and swelling in the airways can cause tissue scarring and damage. That can make symptoms worse, and treatments may become less effective.

People with EA may experience complications or common side effects of the condition. These include:

  • chronic sinus infections
  • inner ear infections
  • nasal polyps
  • aspirin-exacerbated respiratory disease (AERD), which is a type of chronic disease that shares many symptoms with EA

Additionally, eosinophils, the white blood cells that cause this type of asthma, can attack other parts of your body. One common target is your gastrointestinal (GI) tract. If this occurs, you’ll have to seek treatment for resulting symptoms.

Outlook for EA

As doctors and researchers gain a better understanding of the subtypes of asthma, treatments will get better. That means outcomes will improve too.

In the meantime, it’s important for people with EA to get a diagnosis and begin to work with their doctors to find a treatment that promptly addresses symptoms as they occur. Consistent treatment is the key to reducing your risk for complications and for finding treatments that work for you.

It’s also important that you take extra measures to care for yourself if you’ve received a diagnosis of this rare subtype of asthma. Sticking to your treatment plan is only the first step. You should also work to stay physically healthy and listen to your body’s signals for rest. That way, when a flare-up occurs or symptoms worsen, your body is better prepared to fight the inflammation and work with medications to help you get well sooner.