Eosinophilic asthma is a form of asthma associated with high levels of a white blood cell called eosinophils.

In the United States, an estimated 25.7 million people have some form of asthma, and 15% of these people have severe asthma that is difficult to control with standard medications.

Eosinophilic asthma is considered a leading cause of severe asthma, affecting 50-60% of people with the severe form of the disease.

In the population as a whole, eosinophilic asthma is rare, affecting only 5% of adults with asthma.

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Eosinophilic asthma is like other forms of asthma in that people with the condition suffer from inflamed airways, blocked by fluid and mucus, and experience spasms that make it difficult to breathe.

Unlike other kinds of asthma, however, eosinophilic asthma involves abnormally high levels of a particular type of white blood cell called eosinophils.

Eosinophils are part of the immune system and help the body fight off infection. However, high levels of eosinophils can cause inflammation in the airways, affecting the sinuses and nasal passages as well as the lower airways.

In general, as the level of eosinophils increases, inflammation and other symptoms of asthma become more severe.

This form of asthma most often develops in people between the ages of 25 and 35. People with eosinophilic asthma usually do not suffer from allergies. This condition can be difficult to treat and may have a detrimental effect on an individual’s quality of life.

Researchers have not identified a specific cause for eosinophilic asthma. While other forms of asthma are triggered by allergic responses to environmental factors, such as pollen or pet hair, eosinophilic asthma does not develop in this way.

High levels of eosinophils can develop when the body is fighting off a parasitic infection, but scientists have not yet determined what causes these levels to spike in cases of eosinophilic asthma.

Asthma can run in families, so researchers are exploring the possibility of a genetic connection. However, no direct genetic link has been found with eosinophilic asthma.

The symptoms of eosinophilic asthma include:

  • shortness of breath
  • wheezing
  • tightness in the chest
  • coughing
  • obstructed airflow
  • stuffy nose
  • nasal drainage
  • chronic sinus infections
  • anosmia, or a lost sense of smell
  • nasal polyps

Individuals should see a doctor if they frequently experience:

  • shortness of breath
  • coughing
  • wheezing
  • tightness in the chest

Prompt and consistent treatment of eosinophilic asthma is important, as inflammation of the airways can lead to permanent damage, such as a thickening of the airway walls or scarring of the lung tissue.

People with asthma are encouraged to see a doctor at least once a year to make sure their treatment plan is effective. Symptoms that require prompt medical attention include:

  • dizziness or feeling faint
  • wheezing while breathing
  • difficulty doing routine activities

A person should seek emergency care if any of these symptoms develop:

  • quick-acting medication provides no relief after 15 minutes
  • difficulty speaking or walking at a normal pace
  • lips or nails turning blue
  • taking more than 30 breaths a minute
  • breathing causes nostrils to flare and the throat and ribs to feel stretched

The first step in diagnosing eosinophilic asthma is diagnosing severe asthma. The next steps involve evaluating:

  • shortness of breath with exercise
  • airways that stay blocked
  • limited airflow
  • chronic sinus disease
  • nasal polyps
  • response to systemic steroid medications, such as oral corticosteroids

However, the definitive factor in diagnosing eosinophilic asthma is finding high levels of eosinophils. A doctor can measure these levels by analyzing a person’s blood, sputum, or saliva, or by conducting a bronchial biopsy.

Researchers have noted that the symptoms of eosinophilic asthma differ from classic asthma and, in fact, more closely resemble those of chronic pulmonary obstructive disorder (COPD).

In addition to these asthma medications, doctors may prescribe antibiotics to treat the sinus infections that frequently accompany this form of asthma.

People with eosinophilic asthma may also experience:

This condition is also linked to other conditions characterized by high levels of eosinophils. Although eosinophil-associated diseases are uncommon, they are a growing problem around the world, especially when they attack the gastrointestinal system.

An estimated 8.4% of the U.S. population has asthma of some sort. However, as scientists learn more about the condition, they are discovering that “asthma” may be an umbrella term describing a number of different chronic respiratory diseases.

Each one of these conditions, including eosinophilic asthma, requires a specific form of treatment.

Until recently, oral corticosteroids were the standard treatment for eosinophilic asthma. Although many people respond well to these medications, they are not always successful at controlling this disease. Some people also became dependent on this medication.

Doctors are now using new treatments called biologic therapies to treat this condition. They may also use medications known as leukotriene antagonists to reduce inflammation.

Although the connection between eosinophils and asthma has been known since 1889, researchers are continuing to investigate the best way to treat eosinophilic asthma.

The ongoing development of new treatments has significantly improved the outlook for people with this condition.

People with this condition tend to have frequent flare-ups and can become heavily dependent on oral corticosteroids, which have serious side effects. The disease can even be fatal.

Thanks to new treatment options, this does not have to be the case. However, people with eosinophilic asthma must stick to their treatment plan and practice self-care to keep themselves in the best health possible.