Allergies and Asthma – What’s The Link?

Many people don’t realize but the wheezing and coughing of asthma are often triggered by the same things that cause the runny nose and itchy eyes of allergies.  Some people seem to only have asthma and others only allergies, but many find that the two go hand in hand.  It is estimated that up to 90% of children and 50% of adults who are asthmatic also have at least one allergy.  Allergy induced asthma is considered a specific type of asthma and it is the most common kind.

The connection is the allergen, usually inhaled such as pollen, dust mites, or pet dander.  Some people find that they have nasal or asthma symptoms when coming in contact with something or eating specific foods. The allergen causes a reaction, but the reactions differ from one person to the next.asthma-inhaler

If you have an allergy you are more likely to develop asthma.  While many believe it is a genetic link, research has shown that it is possible to develop the problem from having active nasal allergies.  It is felt that untreated postnasal drip can take the allergen lower in the respiratory tract and irritate lungs which in turn leads to asthmatic symptoms.  Those with nasal allergies need to keep them under control so that they won’t set off an asthmatic reaction in their lungs.

The other direction is important too – if you have asthma you may need to be tested for allergies to help know what triggers you have.


The similarities between allergies and asthma

So why are allergic reactions and asthmatic attacks so similar?  It is basically a similar response, just in two different areas of the body.  The connection is the allergen, usually inhaled such as pollen, dust mites, or cat or dog dander.  There are also people who find that they have nasal or asthma symptoms when coming in contact with something or eating specific foods.  The allergen causes a reaction, but the reactions differ from one person to the next.

When exposed to an allergen your body produces IgE antibodies against the substance or organism.  Your body believes it needs to fight off the invader so it reacts.  The IgE affects cells that in response release histamine.  Histamine causes irritation where ever it is located, and your body reacts based on location. When this occurs in your nose you experience symptoms of allergic rhinitis – runny nose, sneezing, and congestion.  If it happens in your lungs, you develop the symptoms of coughing, wheezing, and shortness of breath.

But why?

The reason that some people react to the same allergen with allergic responses in the nose and others react with asthma symptoms in the lungs has never been determined.  It is thought to have a genetic basis, but it is going to require more research to determine the actual genes involved.  It seems that we are hard-wired by our genes to either react with asthma, allergy, or both.


Controlling the Problem

One of the first things anyone with an allergy, asthma, or allergic asthma does is to try to avoid the trigger.  Sometimes this is easy and with other allergens it can be very difficult.  If the allergen is something in the air such as pollution or pollen there is only so much control you have over exposure.  Staying inside, in filtered air (e.g. by using air purifiers), can really help but sooner or later you will need to leave your sanctuary.  When someone is allergic to dust mites they can help themselves with mattress and pillow covers and good house cleaning on a regular basis, but they will always have some exposure.  If you react with specific food allergies you may be able to avoid them completely. Likewise a pet allergy (read this post) will need specific action.

Seasonal changes cause problems.  In the fall, October to December, the change in weather brings people indoors.  Windows are shut and people become exposed to higher concentrations of indoor allergens like dust and pets.  Asthma attacks become more frequent and indoor allergies can really start to bother some people.  Be especially alert to the seasonal change issues so that you can work on them immediately before they set off significant reactions.

Hang drying laundry indoors can increase symptoms too.  While some with asthma feel that dry air is a problem, moisture in the air can create its own set of issues.  Moisture in the clothing hung out around the house goes into the household air, making it easier for mold and dust mites to survive and multiply.  It has been estimated that 30% of moisture in our homes can be attributed to clothes drying inside.  Limit clothes drying to only certain areas of the house and pick an area that gets lots of sun light (to kill mold spores and dust mites).  This will help keep the amount of moisture in the rest of your home to a reasonable level.

Controlling allergies can lead to better control of asthma.  Some people find that if they control the former, they don’t need treatment for the latter.  For children and toddlers, controlling pediatric allergies may make it more likely for them to outgrow their asthma by the time they are adults.


Treatment Options

What you decide for in terms of treatment will vary by how severe your problems are.  Managing the problem will involve you needing to work closely with your health care provider.

If you have allergies, whether you have asthma or not, you need to have a plan when they flare up.  You can avoid triggers, but not completely.  To start with you will probably need antihistamines and decongestants.  You may find that over-the-counter drugs are all that you need.Antihistamines

If your symptoms cannot be controlled then you need prescription medications from your doctor.  He can prescribe different antihistamines, corticosteroids, bronchodilators, leukotriene modifiers, or mast cell stabilizers.  Each drug works in a different way to help keep allergy symptoms under control.  Immunotherapy (“allergy shots”) can work for various allergens, with some people getting significant relief.

Asthma really cannot be treated with over-the-counter medications.  Usually you will have a combination of drugs because some are meant for long-term control while others are used for short-term relief of an attack.  Inhaled steroids, theophylline, and short-acting beta agonists are the older treatments.  More recently leukotriene modifiers (such as Singulair), long-acting beta agonists, and combination inhalers are being used for long term control.  Improved short-acting beta agonists, ipratropium, and newer steroids are used for quick relief.   A new long acting drug, omalizumab, is used with severe asthma to alter the immune system.

Asthmatic bronchitis can be a complication for those with asthma. Asthma is an inflammatory process and in bronchitis, the airways also become inflamed, usually due to exposure to a virus or bacteria.  Asthmatics can develop bronchitis from various types of exposures such as smoke, dust, medications, food, pets, weather changes, exercise, or even strong emotions.  Many times treatment means increasing use of asthma medications that decrease inflammation.  If bacteria are thought to be the cause, an antibiotic will be needed.


Allergy and asthma come from the same triggers and the same reaction in the body.  They even involve the same body system, respiratory.  The main difference is the specific location symptoms—either upper or lower respiratory tract.  Always do what you can to limit exposure to triggers and have a treatment plan ready.  Keep your allergies under strict control and you should be able to minimize asthma attacks.


Further resources – Some allergies and asthma organizations:

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>