What Allergies Cause Asthma?
With allergy season under way, pharmacists can help patients identify triggers and coach them on how to manage.
For those with allergies, the immune system treats these as if they are harmful substances, causing a cascade of events including inflammation and the production of immune response modulators.
Asthma attacks can be triggered by allergies. Allergic asthma is the most common type of asthma. An allergic response causes histamines and immunoglobulin E (IgE) to be released. Too much IgE can cause inflammation of the airways, resulting in an asthma attack.1
The most significant allergens for individuals with allergic asthma are those that are inhaled. Respiratory allergies occur in about 24.4 million individuals in the United States. Food allergies can cause asthma, though that is rare. About 4.8 million children suffer from food allergies.2
The symptoms of allergic asthma are basically the same as nonallergic asthma and include chest tightness, coughing, fast breathing, shortness of breath, and wheezing.1
Common triggers include as follows1:
Cockroaches. These insects live everywhere, from the coldest spots on Earth to tropical areas. The body parts, feces, and saliva of cockroaches are thought to be allergens.
Dust mites. These are microscopic, spiderlike insects that feed on human skin flakes. Dust mites can be found in bedding, carpets, clothing, furniture, mattresses, pillows, stuffed animals, and upholstered furniture. As with cockroaches, both the body parts and feces of dust mites are thought to be allergens.
Food allergens. Foods that can cause allergic asthma include cow’s milk, eggs, fish, peanuts, shellfish, soy, sulfites (often used as preserva- tives), and tree nuts.3
Mold. Mold can grow anywhere moisture is present. Outdoors, molds live in the soil and on leaves and other plant debris. Inside, mold can be found in damp basements, near leaky pipes, or in wet shower stalls, among many other places. Mold reproduces by producing tiny spores that become airborne.
Pets. Pet dander, feces, hair, and saliva are all considered allergens. Individuals with pets can carry these allergens around with them so they can be found where no animals have been.
Pollen. Pollen is produced by plant life, mostly male species of flowering plants. These airborne particles are a common respiratory allergen. These often have a peak season of production but can live in a home and in air ducts year-round.
Below are ways to avoid triggers.3
- Use insect sprays but not near people.
- Use roach baits or traps.
- Avoid curtains and drapes and use plain window shades instead of mini-blinds.
- Change filters on air conditioners and furnaces regularly.
- Control indoor humidity.
- Cover air ducts with filters.
- Encase box springs, mattresses, and pillows in anti-allergen, zippered covers.
- Install noncarpet flooring.
- Keep only washable stuffed animals.
- Reduce clutter.
- Store books and clothes in closed closets or drawers.
- Use bedding and pillows that do not contain feathers.
- Air out damp, humid areas.
- Avoid raking leaves or working with hay or mulch.
- Buy cleaning products that kill and prevent mold.
- Keep plants out of bedrooms.
- Remove clothes from the washer as soon as the cycle finishes.
- Steer clear of areas where mold may flourish, such as basements, crawl spaces, and garages.
- Store firewood outside.
- Turn on an air conditioner when possible.
- Use a mold inhibitor when painting walls.
- Avoid owning pets or adopt hypoallergenic pets.
- Bathe pets weekly.
- Forgo long visits to the homes of people with pets.
- Remove carpeting.
- Restrict pet to areas outside bedrooms.
- Avoid hanging clothes outside to dry.
- Keep windows closed during pollen season.
- Limit time outside during periods of high pollen.
- Wash body and clothing when coming in from outside.
- Wear a mask when gardening, mowing, weeding, etc.
Treatment options include as follows.4
Antibody treatment. This treatment involves medications that prevent the cells of the body from initiating an inflammatory response. These treatments are reserved for patients with severe asthma that is not controlled by other means.
Antileukotriene drugs. These drugs inhibit the effects of the leukotrienes that are produced as part of an immune response, reducing inflammation.
Immunotherapy. Immunotherapy introduces a small amount of allergen into the patient regularly. Once the body is used to being exposed to the substance(s), it has less of a reaction. This is done via injection or as a sublingual tablet. Drawbacks include that costliness, and it takes a number of years for a patient to build up a tolerance.
Inhaled corticosteroids. If a rescue inhaler is being used too often, a physician may prescribe an inhaled corticosteroid as a maintenance medication. These medications act to decrease inflammation. Inhaled corticosteroids may keep the lungs working better after future asthma attacks if used regularly.
Long-acting bronchodilators. These are used regularly to reduce the quantity and severity of asthma symptoms. These are usually dosed twice daily, and the effect lasts about 12 hours.
Oral corticosteroids. These medications are usually only used for
severe attacks. They act by decreasing inflammation in the lungs. Long-term use of oral corticosteroids can lead to serious adverse effects, so these are used only as a short-term treatment.
Rescue inhalers (short-acting bronchodilators). These medications work quickly to open the airways in the lungs. Everyone with asthma should have a short-acting bronchodilator. The effects last from 4 to 6 hours.
It is important to consider that while there is a strong connection between allergies and asthma, not everyone with allergies will have an asthma attack and not everyone with asthma has allergies.
Many individuals have more than 1 trigger, so it is important to be aware of different triggers when trying to manage symptoms. Triggers can also change over time, and individuals can develop allergies at any time in life.
Being informed and taking steps to limit exposure can help effectively manage allergies and asthma.
Kathleen Kenny, PharmD, RPh, has more than 25 years of experience as a community pharmacist and is a freelance clinical medical writer based in Colorado Springs, Colorado.
- Allergens and allergic asthma. Asthma and Allergy Foundation of America. Updated September 2015. Accessed March 12, 2021. https://www.aafa.org/allergic-asthma/
- Allergies and hay fever. CDC. Updated March 1, 2021. Accessed March 12, 2021. https://www.cdc.gov/nchs/fastats/allergies.htm
- Allergies and asthma: they often occur together. Mayo Clinic. March 12, 2021. Accessed March 25, 2021. https://www.mayoclinic.org/diseases-conditions/asthma/in-depth/allergies-and-asthma/art-20047458
- Cattamanchi A. What are my treatment options for allergic asthma? Questions for your doctor. Healthline. April 12, 2019. Accessed March 25, 2021. https://www.healthline.com/health/allergic-asthma/treatment-options-doctor