The Allergy/Asthma Connection
The terms “allergy” and “asthma” are often mentioned together. What is the connection between the two? How are they alike and how different?
What are Allergies?
Allergies cause the body to have a physical response to substances known as allergens. When this response occurs, the immune system is overreacting to a substance that does not cause any reaction at all in most people. Allergic reactions can involve any part of the body, but the most common symptoms include:
- Nasal stuffiness
- Runny nose
Many different substances cause allergic reactions. Some are toxic, such as exhaust fumes, and others are non-toxic, like pollen and food. The most common allergens include:
- Pollen from trees, grasses and weeds
- Dust mite particles
- Tobacco smoke, paint fumes, gasoline fumes, etc.
- Pet dander (skin, saliva, hair or fur)
- Mold spores
- Foods (most commonly, peanuts, shellfish, milk, eggs and wheat)
The rarest type of allergy is called anaphylactic shock. This is a severe reaction that can affect many organs at once. Symptoms include rapid decrease in blood pressure, rash or hives, difficulty breathing, abdominal pain, swollen tongue or throat, diarrhea, fainting and sometimes death.
Overreaction of the Immune System
Essentially, an allergic reaction occurs when the body sends a signal to the immune system that a harmful substance is present. When one of these substances enters the body—pollen, for example—the person with an allergy develops an excess of an antibody called immunoglobulin E (IgE). These IgE antibodies react with allergens to release histamines. It’s the histamines that produce the allergic symptoms—stuffy nose, sneezing, etc.
People can develop allergies at any time in their lives. You could spend your childhood playing in the woods and never develop a poison ivy rash, but then be exposed to it as an adult and have a severe reaction. Researchers aren’t sure why some people have these allergic responses and others don’t, but having allergies does tend to run in families.
Treatments for allergies include:
- Avoiding exposure to the allergen
- Taking over-the-counter medication
- Taking prescription medication
- Receiving immunotherapy, or allergy shots
- Changing the diet
- Getting acupuncture treatments
- Taking homeopathic medicines
What about Asthma?
Asthma is a condition that is triggered by allergens. This may make it sound like asthma and allergy are the same, but that’s not the case. As asthma attack is a different process than an allergic reaction. Some of the symptoms are similar, such as wheezing, but shortness of breath, the most common asthma symptom, is not a common allergy symptom. The treatments for these conditions are different too.
A lot of people who suffer from allergies have asthma too, and some of them aren’t even aware of it. People who have allergies and asthma can eliminate asthma attacks if they can eliminate exposure to the allergen.
When a person has an asthma attack, the airways become blocked or narrowed. Shortness of breath and other breathing problems are the result. The symptoms are almost always temporary and easily controlled. But sometimes the attacks are severe, and in some cases, emergency treatment is necessary.
Asthma triggers include:
- Cold air
- Non-toxic environmental irritants (dust mites, mold, pollen, animal dander, cockroach debris)
- Toxic environmental irritants (paint fumes, smog, aerosol sprays, perfume, tobacco smoke)
- Some viral infections
What Happens During an Asthma Attack?
Here’s how an asthma attack occurs: when an asthma trigger enters the airways, it goes from the trachea (windpipe) into a series of smaller tubes called the bronchi and bronchioles. The tissues inside these tubes become inflamed. The muscles on the outside of the airways tighten up, causing the airways to narrow. Then mucous enters the airways, and the airways become swollen. This swelling causes the airways to narrow even more. It’s easy to understand why this process makes it difficult to breathe.
A study published in the Journal of the American Medical Association points out how effective it can be to reduce exposure to asthma triggers. During the 1996 Olympics in Atlanta, driving in the city was strictly limited for a 17-day period. Air pollution dropped. In that time, Medicaid claims for asthma-related emergency care visits and hospitalizations decreased by about 40 percent. Visits by HMO patients dropped by about 44 percent, and two large pediatric emergency departments reported an 11 percent decrease.
Treatments for asthma include:
- Avoiding the triggers that cause asthma attacks
- Inhaled corticosteroids
The relationship between asthma and allergy, and why people develop these conditions, continues to be studied. But the most important thing to keep in mind is that if you have asthma, learning how to eliminate exposure to the allergen, or trigger, that causes the attacks is your best bet for controlling symptoms.
Sources: American Academy of Asthma, Allergy and Immunology; Asthma and Allergy Foundation of America; E Cutler. Winning the War against Asthma and Allergies. Delmar Publishers, Albany, New York, 1997. Journal of the American Medical Association, February 21, 2001.