When you have allergies your body creates a response to something it thinks is a threat — the allergen. It fires up all of its defenses to try and fight off danger. This is done by your immune system. Your immune system typically works to protect you from disease. When your immune system thinks that there’s danger, it releases a chemical called immunoglobulin E (IgE). This substance is meant to fight back and protect your body. However, high amounts of IgE can cause your airways to tighten, making it difficult to breathe.

Asthma is a disease of the lungs that causes your airways to:

• Become swollen or irritated (called inflammation) specifically in the airway linings.
• Produce large amounts of mucus that is thicker than normal.
• Narrow because the muscles around the airways tighten.

How common is allergic asthma?

Many people with asthma actually have allergic asthma. It’s the most common type of asthma. In the United States, about 25 million people have asthma. Out of that group, approximately 60% have asthma that’s caused by allergies.

Symptoms and Causes

What causes allergic asthma?

The cause of asthma isn’t known. However, for those with allergic asthma, the reason symptoms start is related to allergens. This is the main difference between allergic asthma and other types of asthma — allergens are inhaled and trigger asthma symptoms. When you experience severe asthma symptoms, it’s called an asthma attack.

What are common allergens that can trigger allergic asthma?

Allergens can be found all around you. These can be in your indoor and outdoor environments. When you have allergic asthma, inhaling these allergens can set off (trigger) your symptoms. It’s important to know what can trigger your asthma so that you can control your condition.

Possible allergens that can trigger allergic asthma can include:

• Dander: This is skin flakes and it’s usually from pets. Hair is often grouped with dander as a common allergen.
• Pollen: A powdery substances, pollen comes from plants. The most common types of pollen that trigger allergic asthma are grass and weeds.
• Mold: Typically found in places that hold moisture (basements), mold produces spores that get into the air and can trigger your asthma.
• Dust mites: Very small and shaped like spiders, dust mites live in the soft surfaces of your home (carpets, soft furniture coverings and clothes). They eat skin flakes that you naturally shed all of the time. Both the mites themselves and their feces are allergens.
• Cockroaches: These pests can be found in many homes and other buildings. Your asthma can be triggered by the feces, saliva and other body parts of the cockroaches.

Some people suffer from seasonal allergies. These are allergies that flare up at a certain time of year. This is often connected to spring because of the blooming of many plants. During this time of year, there is more pollen in the air than other seasons (fall or winter).

What are the symptoms of allergic asthma?

If you have allergic asthma, you may have many of the same symptoms you would experience with other types of asthma. These symptoms can include:

• Feeling short of breath.
• Coughing frequently, especially at night.
• Wheezing (a whistling noise during breathing).
• Experiencing chest tightness (feels like something is pressing or squeezing your chest).

These symptoms can be very intense during an asthma attack. Make sure you have a treatment plan in place if you have severe asthma symptoms — this plan often includes an inhaler (sometimes referred to as a rescue inhaler).

You can also experience symptoms more closely related to allergies. These are usually less intense than asthma symptoms and can happen when you’re exposed to an allergen. These symptoms can include:

• A stuffy nose.
• Itchy or running eyes.
• Sneezing.
• A rash and hives.

Does an asthma attack trigged by allergies feel different than a typical asthma attack?

When you have an asthma attack that’s triggered by your allergies, it is a severe flair up of your asthma symptoms. During an asthma attack, your airways will tighten, making it difficult to breathe. You may also feel chest pressure, wheeze and cough. The symptoms of an allergic asthma attack are the same as an asthma attack caused by something else. The difference between the two is the cause of the asthma attack. When you experience severe asthma symptoms after breathing in an allergen, this is typically allergic asthma.

Diagnosis and Tests

How is allergic asthma diagnosed?

There are several tests that your healthcare provider can do to diagnose allergic asthma. To pinpoint allergies, your provider may do a blood test or a skin test. In these tests, your provider is looking for the effect of the allergens on your body. For a skin test, possible allergens may be applied to small areas of your skin to see how you react to each one. This can be uncomfortable, but it will show your provider what might be causing the reaction.

Your healthcare provider may also do a few tests to diagnose your asthma. These tests are used to make sure that it’s asthma that’s causing your symptoms and no other medical condition. Tests to diagnose asthma can include:

• Spirometry: This breathing test involves taking a deep breath in and then exhaling into a tube. This tube is connected to a computer that will collect information about how well the air moves when you breathe in and out. Spirometry can also be done with a bronchodilator. This version of the test looks at how well your airways relax before and after taking medication. The peak expiratory flow test can also be done during a spirometry test. In this test, you will exhale as hard and as fast as you can into the tube.
• Exhaled nitric oxide test (FeNO test): In this test, your provider will measure the amount of nitric oxide in your breath when you exhale. This may be used in more mild cases of allergic asthma where you might not feel extreme symptoms. In those cases, the test will still detect the nitric oxide.
• Bronchoprovocation test: This test is similar to the allergy tests that may be run on your skin in that your provider will introduce possible allergens to see what causes you to have a reaction. This is done in a controlled environment and your provider will use small samples to avoid a serious reaction. You’ll breathe in possible allergens to see what’s triggering your asthma.

If you have allergic asthma, your symptoms are typically triggers by something you breathe in. Determining what allergen triggered your symptoms is another part of the diagnosis process for allergic asthma. Try to keep a journal or notes of what happened when you experienced asthma symptoms. If you were outside by freshly cut grass, it could be a pollen allergy. If you were petting a dog, it could be pet dander. Figuring out what you inhaled when your symptoms started can help your provider create a plan to control your allergic asthma.