Eosinophilic asthma (EA) is both similar to and different from the familiar childhood form of asthma. Common corticosteroid inhalers alone may not work on EA. Flares may come on suddenly for no obvious reason.

EA is often severe. People who have the disease have high levels of eosinophils, white blood cells that normally help defend your body from infections and other invaders.

The flood of eosinophils swells your whole respiratory system, from your sinuses down to your lungs. That narrows your air passageways and leaves you panting for breath. It also can make you wheeze and cough. Notable traits of EA are that it:

  • Happens mostly in adults
  • Usually isn’t caused by allergies
  • Affects your entire respiratory system
  • May not respond to corticosteroids alone, the main medication for asthma

Who Gets It?

Researchers know that eosinophils are the key agent in this form of asthma. But there’s much they don’t know, including why people get this disease. It could be more common in adults because they are more likely to be obese, have nasal polyps, and have other issues that can lead to EA.


The goal of any asthma treatment is to help you feel as normal as possible with the least amount of medication.

Your doctor most likely will prescribe inhaled corticosteroids, the same therapy as for classic asthma. You can take these drugs for a long time to ease swelling and tightness in your airways.

You’ll also likely take a second medication called a long acting beta-agonist (LABA). It dilates, or expands, your airways by relaxing the muscle around them. It’s usually combined with steroids into one medication.

Uncontrolled Asthma

If your asthma is uncontrolled you’ll need to see your doctor to get it stabilized. Symptoms of uncontrolled asthma include if you:

  • Have asthma symptoms such as coughing, wheezing, or shortness of breath more than twice a week
  • Wake up in the middle of the night with asthma symptoms more than twice a month
  • Find it hard to play, exercise, or do regular activities
  • Need your emergency medicine, called a rescue inhaler, more than twice a week

If you have any of these uncontrolled symptoms, you will need more aggressive treatment. Your doctor may:

  • Change, add, or raise your medication dosage
  • Put you on a short course of oral steroids in pills or a syrup. These strong drugs work well but can cause side effects, some serious, if you use them for a long time

Your Treatment Team

Primary Care Doctor

This may be your internist, family doctor, gynecologist, or gerontologist. Primary care doctors have a good general knowledge of asthma, but they may be unfamiliar with unusual symptoms or how best to use the latest treatments.


This lung specialist is the doctor you’re most likely to see for your asthma diagnosis and treatment. At each visit, your pulmonologist will give you breathing tests to check your lung health.


Many people with EA may not have allergies. But if your doctor thinks they might set off your asthma flares, an allergist can confirm it. They also can teach you how to avoid your allergens and tell you if allergy shots may help.


If those steps don’t help enough, or if you need to take oral steroids more than twice a year, you may need to switch your asthma therapy.

One option is to add on a newer class of drugs called biologics. They’re derived from living organisms, and they block specific actions or agents in the body. In this case, they block the eosinophils that inflame your lungs.

Only a small number of people with eosinophilic asthma need biologics on top of their other medications. The FDA has approved four biologic drugs. Your doctor will consider many things when prescribing one. Among them are your blood eosinophils level, your insurance coverage, and how often you need treatments, which are either shots or IV infusions.

The biologics haven’t been used long enough for researchers to know which ones work best, and for whom. They include:

Benralizumab (Fasenra)

For high eosinophil count, above 300 cells/microliter. Monthly shots for the first 3 months, then every 8 weeks. You can use a needle pen yourself if your doctor agrees.

Dupilumab (Dupixent)

For eosinophil count above 150 cells/microliter. Single-dose, pre-filled syringe every other week. You will need training to do it at home.

Mepolizumab (Nucala)

For eosinophil count above 150 cells/microliter. You or your caregiver give the shots in your belly or thigh with an autoinjector. The recommended schedule is once every 4 weeks.

Reslizumab (Cinqair)

For very high eosinophil count, above 400 cells/microliter. You will go to your doctor’s office every 4 weeks for an IV session that lasts 20-50 minutes.

Your doctor may watch you for 3-6 months for improvements. And if the biologics work, ask your doctor when you should stop taking them. Biologics can work very well for some people who haven’t been helped by other types of drugs. But they don’t help everyone. Biologics are also expensive and can set off a serious allergic reaction or other side effects.

How to Prevent Your Flares

People who have asthma are often unfamiliar with the warning signs of an impending attack. A flare may come on slowly, and you may not recognize it until you realize it all of a sudden.

One good way to keep on top of your symptoms is with an asthma diary. Record your symptoms and note the time, location, and what you were doing to get an idea of what triggers your flare-ups. Use a peak flow meter to monitor how well air moves through your lungs. It can alert you to a possible asthma attack hours or even days before it arrives.

Unlike with classic asthma, most people with eosinophilic asthma may not have allergies. A flare might strike suddenly without a clear reason. Still, pinpointing possible triggers can help you prevent breathing troubles. As many as 7 out of 10 people don’t take their asthma drugs every day. This can make flares more likely. It’s also important to treat other conditions you may have, such as diabetes, sleep apnea, or sinus problems.

Know your triggers, which may include:

  • Irritants like cigarettes smoke, fireplace smoke, and chemical cleaners.
  • Very cold or very hot weather. Stay inside, especially if the air quality is poor.
  • Exercise. Use your quick-relief medicine 15-30 minutes beforehand if workouts set off your symptoms.
  • Stress, which makes you breathe more quickly and set off a trigger.
  • Cold and flu viruses. They’re a common cause of asthma flare-ups. Wash your hands often, and get vaccinated against the flu and pneumonia.

How to Handle Your Flares

An EA flare can turn serious quickly. Your symptoms may be subtle and seem unrelated to your asthma. Early warning signs could be a cough or feeling out of breath after normal activity.

Always have your rescue inhaler on you. Use it as soon as you notice these symptoms. Your doctor can give you a written asthma action plan that explains what medication to take during a flare and when to call your doctor. Call 911 if:

  • Your breathing doesn’t get easier within 10 minutes or your symptoms worsen
  • Your lips or fingernails turn or bluish or grayish
  • Your breathing worsens or you have trouble walking
  • Your peak flow is less than 50% of your personal best, or less than 70% if you have frequent asthma attacks

Even if you don’t need emergency care, it’s a good idea to follow up with your doctor. Let your loved ones know what they should do in case you have an asthma attack and how to tell if they need to call 911.

Future Therapies

Researchers have several other biologic drugs in the pipeline. They include:


This drug blocks thymic stromal lymphopoietin (TSLP), a protein linked with EA. It’s being tested on adults with severe, uncontrolled asthma who haven’t responded to other therapies.

Interleukin-33 (IL-33) antibody

People with severe asthma, including eosinophilic asthma, have high levels of a substance called interleukin-33. But antibodies that block this protein have shown promise in controlling eosinophilic asthma.


This experimental drug blocks prostaglandin D2, a substance that causes the airways to tighten and triggers an asthma flare. One study of people with EA found that it greatly lowered the number of eosinophils in the blood. But it’s unclear how much it relieves asthma symptoms.