Asthma is one of the most common chronic illnesses in the United States that affects both children and adults. There are different subtypes of asthma based on the cause. Allergy-induced asthma is one of the most common forms of asthma.
What Is Allergy-Induced Asthma?
To understand what allergy-induced asthma involves, it is helpful to learn what happens during an allergic response. In an allergy response, the immune system overreacts and mistakes a harmless substance as dangerous.
This response causes a release of chemicals to fight the “invader.” The substances released lead to typical allergy symptoms, such as a runny nose, itchy eyes, and congestion.
In some people that have allergies, the reaction also occurs in their lungs resulting in allergy-induced asthma. The antibodies released by the immune system including IgE can trigger inflammation in the airways, which causes common asthma symptoms.
Although the association between asthma and allergies is strong, it’s essential to understand there are also other causes of asthma. Stress, exercise, and cold weather can trigger asthma symptoms.
Also, it’s common for people with asthma to have more than one trigger. For example, a person with asthma can have both exercised induced asthma and allergy-induced asthma.
Understanding the possible causes of asthma symptoms is needed to develop appropriate prevention strategies.
Allergy-Induced Asthma Statistics
According to the Asthma and Allergy Foundation of American, about 25 million people in the United States have asthma. Of those people, about 60 percent have allergy-induced asthma. For school-age children that number may be closer to 80 percent.
The overall number of people with allergy-induced asthma as well as asthma, in general, appears to be growing. According to the Centers for Disease Control and Prevention, about one in 12 people now have asthma. That number was one in 14 in 2001. The reason for the increase in asthma is being studied but is not currently known.
Allergies even without asthma symptoms often interfere with school and work. When allergy symptoms lead to asthma, it is often a major cause of missed school. According to the Asthma and Allergy Foundation of American, asthma is the top reason for missed school.
Causes of Allergy-Induced Asthma
The exact reason why some people develop allergy-induced asthma is not fully understood. It does appear that having a family history of allergies puts you at an increased risk. If you have allergies, such as hay fever, it also increases your risk of also developing asthma symptoms.
Although it’s not entirely clear why some people develop allergies, common allergens have been identified. The following substances are common triggers for people with allergy-induced asthma:
- Dust Mites: Dust mites are too small to see with the naked eye, but they can still lead to allergies. Dust mites are a common allergen found in carpets, pillows, and bedding. They are also found in mattresses, stuffed toys, and upholstered furniture. The mites themselves, as well as their feces, are considered allergens.
- Pets: Dogs may be man’s best friend, but pets can also lead to allergy symptoms. Pet dander, which is skin flakes, as well as pet urine, hair, and salvia can all be allergens.
- Pollen: Pollen is one of the most frequent allergens, which can lead to asthma symptoms in people that are sensitive. Pollen is a microscopic substance found in grasses, weeds, and trees. It becomes airborne and can easily be transported inside your home. Pollen counts vary depending on what types of flowers are in bloom.
- Mold: Mold is another common allergen for people with allergy-induced asthma. When moisture is present, mold can grow on most things. Outside, mold often lives on the trees, plants, or in the soil. It can also be found indoors anywhere that tends to become damp. For example, moisture in areas, such as the bathtub, shower, or basement, can lead to mold growth. Tiny mold spores can become airborne easily and get into the lungs.
Although the substances listed above are common allergic asthma triggers, many other substances can also be allergens. Also, it’s common for people with allergy-induced asthma to be allergic to more than one thing.
Allergy-Induced Asthma Symptoms
Allergies can cause certain respiratory symptoms without having an asthma component. Allergy symptoms may cause congestion, sneezing, and a runny nose. Allergy-induced asthma symptoms tend to be different and affect the lower airways and lungs.
Typical allergy-induced asthma symptoms include:
- Chest tightness
- Shortness of breath
- Increased mucus production
- Nighttime waking with asthma symptoms
Allergic asthma symptoms may start as soon as the person is exposed to the allergen. Symptoms often continue even after the exposure is over.
The severity of symptoms can also vary from mild to life-threatening. In some cases, the airways can become severely inflamed and constricted, which makes breathing difficult.
Diagnosis of Allergy-Induced Asthma
Even if you think your asthma is triggered by allergies, it’s important to see a doctor. An allergist or immunologist can perform tests that will confirm a diagnosis of allergy-induced asthma.
One of the first steps to diagnose allergy-induced asthma is a medical history review and physical exam. A medical history review includes information on whether asthma symptoms have a pattern. For example, the doctor may ask if asthma symptoms occur after spending time outdoors or develop more often during certain seasons.
If allergy-induced asthma is suspected, additional testing is often needed. Your doctor will likely perform a variety of tests to make a diagnosis. Below are common tests used to diagnose allergic asthma.
Occupational asthma can be developed when irritants are inhaled on the job. Jobs at risk include construction, painting and farming.
Allergy Skin Testing
Allergy skin testing involves introducing small amounts of potential allergens into the body through a skin prick with a needle. The amount of the allergen injected into the skin is very small.
If a person is allergic, they will have a mild response but not a severe reaction, such as a full-blown asthma attack. An allergy skin test helps the doctor pinpoint what is causing allergic asthma.
Spirometry helps diagnose all types of asthma including allergy induced. The test involves taking a deep breath and measuring the amount of air you can inhale and exhale as well as how fast you breathe in and out. Spirometry also helps your doctor determine the severity of your asthma and determine if treatment is effective.
Exhaled Nitric Oxide Test
The test measures the amount of nitric oxide exhaled from a breath. Increased levels of nitric oxide occur with swelling of the airways.
The exhaled nitric oxide test is used to determine the amount of lung inflammation present in people with allergic asthma. It can also determine how effectively inhaled steroids decrease inflammation.
Allergy-Induced Asthma Treatment
Treatment is aimed at preventing allergy asthma symptoms and treating symptoms when they do occur. Certain treatments are specifically aimed at controlling allergies which in turn prevents asthma symptoms.
There are also medications that treat both allergy and asthma symptoms. A comprehensive allergy-induced asthma treatment plan usually includes the following:
Preventing allergy-induced asthma flare-ups is one of the most vital aspects of treatment. Prevention involves identifying and reducing allergens. Depending on what allergen is triggering an asthma attack, there are several ways to decrease exposure.
Consider some of the following suggestions to decrease specific allergens:
- Dust Mite Allergies: For those that are allergic to dust mites, using mite-proof bed covers on pillows and mattresses is helpful. It’s also important to wash pillows, comforters, and all bedding in hot water at least 140 degrees to kill mites.
- Pollen Allergies: If you have a pollen allergy, it can be difficult to decrease all exposure. But there are a few things you can do. Check the pollen count each day and try to stay indoors as much as possible when counts are high. Wash your face as soon as coming in from outside to remove pollen. Wear sunglasses when outside to decrease pollen in the eyes.
- Pet Allergies: If you have a pet allergy leading to asthma symptoms, there are several things you can do. In some cases, you may want to consider reducing your exposure. If the pet lives with you, it can be challenging to decrease exposure, but you can do a few other things. Consider buying an air purifier and place it in the area where your pet spends most of their time. It may help decrease pet dander. Wash your pet and his bed often to decrease the build-up of dead skin cells that can shed. Also, keep your pet off the couch or bed as much as possible.
- Mold Allergies: If a mold allergy is causing asthma symptoms, you can lower your exposure in several ways. When working outside planting, cutting grass, or clearing leaves, consider wearing a dust mask to prevent breathing in mold spores. Use central air conditioning with a HEPA filter to trap spores and prevent them from circulating in your home. Keep humidity level low inside. Use a device called a hygrometer, which can be purchased at a hardware store, to check humidity level. Levels above 50 allow fungi to grow. Ideally, indoor humidity level should be below 45.
Anti-immunoglobulin immunotherapy may also be used to treat allergic asthma.
Anti-immunoglobulin immunotherapy interferes with the release of IgE antibodies during an allergic response. By decreasing IgE antibodies in the bloodstream, it prevents an allergic reaction that triggers asthma symptoms.
An example of IgE immunotherapy is the drug omalizumab (Xolair). It is typically only used in moderate to severe allergy-induced asthma that is not controlled with other treatments.
Anti-immunoglobulin immunotherapy is currently administered as an injection every two to four weeks by a doctor or nurse.
Depending on the severity of your allergy, allergy shots may be helpful in decreasing symptoms of asthma. Allergy shots involve receiving small amounts of the allergen through a series of injections.
The goal of the injections is to build-up a tolerance to the allergen, which reduces an allergic response by the immune system. The treatment can take several months or longer to work.
In addition to decreasing triggers or preventing an allergic response, medication is also often used to treat allergy-induced asthma.
Medication for allergy-induced asthma may include:
- Leukotriene Modifiers: Leukotriene modifiers are a type of medication that treats both allergies and asthma. It is often prescribed to treat allergy-induced asthma. Leukotriene modifiers work by blocking the action of the leukotrienes during the immune response. Leukotrienes play a role in the production of excess mucus and narrowing of the airway muscles. By blocking their action, you decrease the allergic response including asthma symptoms. Leukotriene modifiers is an oral medication, which is taken daily to prevent symptoms.
- Corticosteroids: Some medications, such as corticosteroids, may be prescribed in all types of asthma including allergic. Steroids are used in allergic asthma to decrease inflammation. Corticosteroids can be administered orally or intravenously during an asthma flare-up. Inhaled corticosteroids are also prescribed to prevent asthma symptoms.
- Quick-Relief Bronchodilators: People with all types of asthma including allergy-induced, may need quick-relief bronchodilators to treat sudden symptoms. This classification of medication works by relaxing the muscles of the airways, which makes breathing easier. Example of quick-relief medications includes albuterol and levalbuterol.
The Bottom Line
Treating allergy-induced asthma is like treating two conditions. To prevent asthma symptoms from developing, the root of the problem, which is the allergic reaction, must also be treated. Usually, allergic asthma requires a combination of treatments to prevent and control symptoms.
It’s essentials people with the allergy-induced work closely with their allergist or asthma specialist to develop an asthma action plan that is effective. Keep in mind; it may take a little trial and error before allergy-induced asthma symptoms are under control.