Extrinsic Asthma: How It Differs From Intrinsic Asthma And How To Treat It

What is asthma?

Asthma is a chronic (long-term) condition in which your airways, which carry air in and out of your lungs, become inflamed and narrowed. This condition makes it harder to breathe and results in symptoms such as coughing and wheezing.

It is a fairly common condition that starts during childhood and cannot be cured, although it sometimes goes into remission as children get older.

Asthma is generally divided into two types:

• Extrinsic asthma

• Intrinsic asthma

Difference between extrinsic and intrinsic asthma

Extrinsic asthma is triggered by external factors, while intrinsic asthma is set off by internal ones. In both cases, asthma triggers can lead to a sudden worsening of symptoms, known as an asthma attack or asthma exacerbation. In extreme cases, an asthma attack can be life-threatening.

Extrinsic asthma

If you have extrinsic asthma, your symptoms are triggered by allergens or chemicals. As this is a type of allergic reaction, the immune system goes into overdrive, and an oversupply of immunoglobulin E antibodies is released into the blood.

Extrinsic asthma is the more common (and typically less serious) form of asthma. It is also called allergic asthma or atopic asthma.

Intrinsic asthma

Intrinsic asthma is provoked by factors other than allergens. Here, there is only a small and local release of immunoglobulin E antibodies within the airway passages.

Sometimes called nonallergic asthma or nonatopic asthma, it can be triggered by things such as exercise and stress. It typically starts later in life and is more common in women.

Symptoms of extrinsic and intrinsic asthma

The symptoms of extrinsic and intrinsic asthma are the same. These symptoms can include:

• Coughing

• Wheezing

• Tightness in the chest

• Shortness of breath and trouble breathing

• Increased production of mucus

These symptoms vary in severity between individuals and over time. Acute symptoms, or an attack, can come on quickly and often with little warning. If untreated, these symptoms can rapidly become life-threatening.

Causes and triggers of extrinsic versus intrinsic asthma

Extrinsic and intrinsic asthma have different triggers you should watch out for to help manage your condition.

Triggers of extrinsic asthma

Allergic or extrinsic asthma triggers vary from person to person, but the most common are typical allergens such as:

• Pollen

• Dust mites

• Mold

• Pet dander

• Rodents

• Cockroaches

It's important for people with extrinsic asthma to identify their triggers. An allergy test can help narrow down the specific substances that trigger your asthma.

Triggers of intrinsic asthma

On the other hand, intrinsic asthma is triggered by environmental, physical, and psychological factors. Common triggers are:

• Respiratory infections

• Exercise

• Psychological stress

• Cold or humid weather

• Air irritants such as cigarette smoke and pollution

• Certain medications, such as aspirin

Who is most prone to each type of asthma?

Extrinsic asthma is more common in children and younger adults. A combination of multiple genetic and environmental factors likely contributes to the development of the condition.

Having the genes that predispose you to asthma does not mean you will develop it, but you are more likely to than someone who doesn’t have the genes.

Intrinsic asthma tends to develop during the adult years, generally in people aged 40 or over. It also tends to be more severe than extrinsic asthma. Known risk factors include:

• Obesity, particularly in females

• Smoking, particularly in males

Diagnosis of extrinsic versus intrinsic asthma

The symptoms of the two types of asthma are identical. Doctors may use a spirometry test to measure the airflow in and out of your lungs or chest X-rays, but these methods do not necessarily distinguish between extrinsic and intrinsic asthma.

Instead, doctors rely on additional factors to make a diagnosis. For example, age is an important consideration. The younger you are, the more likely your asthma is caused by allergies. If you are 40 or older and develop symptoms, you are more likely to have intrinsic asthma.

Doctors also take into account the following when diagnosing extrinsic asthma:

• Whether you have another allergic condition, such as eczema, allergic rhinitis, allergic conjunctivitis, or allergic rhinoconjunctivitis. Allergic rhinitis is another name for hay fever, while allergic conjunctivitis causes itchy, red, and watery eyes.

• Whether your symptoms are year-round or seasonal, and whether you experience more attacks indoors or outdoors

• Whether your symptoms are made worse by exercise

• Whether you are on medication that might cause asthma symptoms

• Whether your symptoms are brought on by strong emotions, crying, or laughing

If your doctor suspects you have extrinsic asthma, they will perform an allergy test to determine what you are allergic to, considering when and where you have attacks. For example, if your asthma symptoms are worse in the spring, they will test prevalent pollen types in your area during that season. If your symptoms are year-round and worse indoors, they will test for indoor allergens such as pet dander and dust mites.

Trigger avoidance

A key element of treating extrinsic asthma is to avoid triggers as much as possible. For example, it may be best to stay indoors on high pollen days.

Other suggestions include:

• Dust-proof covers on your pillows and mattress

• Wash bedding frequently in hot water

• Remove stuffed toy animals from bedrooms or put them in plastic containers when not in use

• Clean hardwood floors with a damp rag or mop instead of sweeping

• Keep windows closed when pollen is high

• Go out at times of day when pollen counts are low

• Shower and change clothing after working or playing outdoors

• Hang clothes indoors to dry

• Keep pets out of the bedroom. Doctors will typically recommend avoiding pets you are allergic to, but rehoming any existing pets may not be an option. Pets should also be bathed once a week, and you should wash your hands after petting or handling animals.

• Clean bathrooms, kitchens, and basements regularly

• Keep humidity low

• Store all food in sealed containers and empty garbage regularly to avoid attracting cockroaches

• Vacuum regularly

If you have to go outside on high pollen days, consider wearing a face mask to keep out the pollen, although, for people with severe asthma, this can make it harder to deal with an attack. You should also avoid being around anyone who smokes. Do not allow anyone to smoke in your car or home. Use fragrance-free products as much as possible.

Trigger avoidance for intrinsic asthma can be more difficult, but it may help if you avoid cold, dry, and humid conditions.

Medication

Most people with asthma need two kinds of medication.

Quick-relief medication

Quick-relief medication is a rescue or relief inhaler. You use this inhaler when you feel an asthma attack coming on. It contains a short-acting bronchodilator, typically a beta-2 agonist or an anticholinergic.

The rescue inhaler expands the passageways into your lungs, making it easier to breathe and helping you to clear mucus. It does not, however, treat the underlying cause.

Long-term control medication

Long-term control medication usually takes the form of a maintenance inhaler containing a low dose of a corticosteroid. This medication helps keep inflammation down and reduces the number of attacks.

Some people with asthma also need a long-acting inhaled beta-2 agonist or an anti-leukotriene. This inhaler is used once or twice a day, even when symptoms aren’t present.

If you cannot avoid a trigger, or if avoiding it causes distress, like stopping activities you enjoy, allergy shots can help reduce extrinsic asthma symptoms over time. Shots can also help if you have tried avoiding triggers and still have symptoms. This type of immunotherapy can help reduce asthma symptoms and other allergic symptoms such as hay fever.

Your doctor will work out an asthma action plan, including the right combination of medications.

When to see a doctor

If you or your child has asthma symptoms such as wheezing or struggling to breathe, you should see a doctor right away. An acute asthma attack can be a medical emergency warranting a visit to the ER.

Your doctor will take a medical history to work out when symptoms are happening. If they suspect a particular trigger, they might suggest an allergy test to see if an allergen is causing your extrinsic asthma.

Most people with asthma have regular check-ups to ensure their asthma is well controlled. However, some children with asthma go into remission at puberty. If they continue to be symptom-free for a prolonged period, you can talk to your doctor about stopping their medication.

The lowdown

Asthma is divided into two types, extrinsic and intrinsic. Extrinsic asthma is the most common kind of asthma and is typically caused by allergies. It is most often diagnosed in children and young adults.

If asthma symptoms appear later in life, it is more likely to be intrinsic. Triggers of intrinsic asthma are more difficult to manage as they are sometimes environmental factors and are not as easily identifiable.

While asthma cannot be cured, it can be managed with a combination of medication and reduced exposure to triggers. When left untreated, asthma can cause life-threatening complications. It is important to talk to your doctor if you are experiencing asthma symptoms to help adjust your health plan.