This lesson explores the meaning of allergies and asthma and how they may interact with one another at the same time. You'll learn about allergic rhinitis, intrinsic asthma and extrinsic asthma as well as the signs, symptoms, and treatment options of each.
Allergies and Asthma
Allergies and asthma - they're not always linked, since asthma can result from non-allergic components, but they do seem to go together like two peas in a pod. This lesson focuses on the allergic-based aspect of asthma, what triggers it, how it makes a person feel, and what treatment options are available and how they work.
What Is an Allergy?
An allergy is technically defined as an overreaction by the body's immune system to a normally harmless substance. It's kind of like people who just completely freak out at the sight of a mouse or bug that's more afraid of the person screaming than the other way around.
Your immune system contains a collection of molecules and cells that release substances to fight off disease. But sometimes, this arsenal of weapons and soldiers is unleashed on completely harmless things. The substances that trigger an allergic reaction are called allergens and include environmental allergens, such as:
- Dust mites
- Pet dander
One problem caused by allergies is allergic rhinitis. Allergic rhinitis is an allergen-induced inflammation of the nasal membranes that results in your stereotypical congestion, itching, and sneezing.
What Is Asthma?
Upwards of 78% of people with asthma have allergic rhinitis. Asthma is defined as chronic airway inflammation, resulting in airway swelling and narrowing and subsequent recurring episodes of coughing, wheezing, chest tightness, and breathlessness. It can be brought upon by, not surprisingly, an allergen.
But importantly, there are other factors, non-allergic causes, which can cause asthma, that I do want to mention for completeness's sake. These include:
- Respiratory tract infections
- Cold or dry air
- Sensitivity to medications
- Hormonal changes (such as those during pregnancy)
- Stress and anxiety
Overall, asthma triggered by an allergic reaction, to things like the environmental allergens I mentioned before, is termed extrinsic asthma. This is in contrast to intrinsic asthma, which is asthma triggered by non-allergic components, like the things I just mentioned: the cold air, exercise, respiratory infections, and so forth.
Asthma affects between five and ten percent of the U.S population. It is more frequently found in children than adults and results in about 2 million emergency room visits every year. So, it's no small problem!
Treating Allergies and Asthma
There is no cure for asthma, and many allergies are also difficult to control. This doesn't mean a person with either or both cannot live a good life; there just has to be appropriate treatment strategies employed to guarantee the highest quality of life possible.
The most obvious thing that anyone can do is to avoid the allergen that is triggering their asthma problem. Of course, this isn't always possible as a result of the person's environment or personal choices, like not wanting to give up a favorite pet.
Therefore, allergy medication, such as antihistamines and corticosteroids, can be used. These two types of medications tell your immune system to calm down. It's like giving an anxiety medication to a person who is overly terrified of certain animals, bugs, or social situations. Except in this instance, we're giving a pill to our immune system to relax it a little bit.
There are medications we can give beyond this, of course, such as nasal decongestants to try and help mitigate the allergic rhinitis. Decongestants help to relieve all that swelling by basically turning off the faucet to the area that is swelling up with fluid. Meaning, the blood vessels there are forced to constrict and close by this medication so that fluid doesn't leak out into the surrounding tissues as a result of the allergic reaction.
There are other things we can do to mitigate allergic reactions. Allergy shots can be given over a long period of time to help minimize allergic reactions. Allergy shots are like school for your immune system. Giving these shots teaches your body that these allergens are not something to overreact to. It's like some people are gradually introduced to snakes over a long period of time to get rid of their fear and build tolerance to snakes. Here, we're introducing our immune system to allergens so it tolerates them, doesn't fear them, and doesn't overreact to them.
And, of course, everyone knows that people with serious allergies carry around a shot of epinephrine, a hormone that helps to counter the effects of a severe allergic reaction.
Treating the allergy in a person with asthma triggered by these allergies is only one component here. We must also consider that medications exist for the signs and symptoms triggered by the asthma itself. Corticosteroids can be inhaled to reduce inflammation, and beta agonists can also be inhaled in order to open up the constricted airways. The opening up of constricted airways is known as bronchodilation, and that is why these medications are called bronchodilators. This medication 'relaxes' your airways, like you would relax and open up a clenched fist, and this allows the airways of your lungs (the bronchi and bronchioles) to expand (or dilate).
This lesson should have taught you that an allergy is an overreaction by the body's immune system to a normally harmless substance.
The substances that trigger allergic reactions are called allergens, and they include dust mites, pollen, mold, and pet dander.
One problem caused by allergies is allergic rhinitis, an allergen-induced inflammation of the nasal membranes that results in your stereotypical congestion, itching, and sneezing.
Many people with allergic rhinitis also have asthma. Asthma is chronic airway inflammation resulting in airway swelling and narrowing and subsequent recurring episodes of coughing, wheezing, chest tightness, and breathlessness.
Asthma can be caused by the allergens I just discussed before. However, non-allergic causes of asthma are possible and include exercise, cold air, and respiratory infections.
Asthma triggered by a reaction to an environmental allergen is termed extrinsic asthma. This is in contrast to intrinsic asthma, which is asthma triggered by non-allergic components.
Allergies can be treated with antihistamines, corticosteroids, and allergy shots. Asthma is often treated with inhaled forms of beta agonists, which result in bronchodilation. The opening up of constricted airways is known as bronchodilation.
After this lesson, you'll be able to:
- Define allergy and allergens
- List common allergens
- Summarize what happens during allergic rhinitis
- Describe what asthma is and tell what causes it
- Differentiate between extrinsic and intrinsic asthma
- Explain how allergies and asthma are treated