Allergic asthma refers to asthma triggered by exposure to allergens. It is the most common type of asthma. About 60 percent of people with asthma have allergic asthma.1
Allergens are harmless substances that your body thinks are harmful. Your immune system may react to an allergen in a way that leads to airway inflammation. Common allergens that trigger asthma include dust mites, mold, and pet dander.1
Talk to your doctor to identify which allergens trigger your asthma. They can also recommend medicine and lifestyle changes to reduce your symptoms.
What are symptoms of allergic asthma?
Allergic asthma has the same symptoms as many other types of asthma. This includes:2
- Shortness of breath
- Chest tightness
The key difference is that allergen exposure triggers symptoms. Common indoor and outdoor triggers of allergic asthma include:1
- Dust mites
- Pet dander
Other substances may also trigger asthma attacks for people with allergic asthma. This includes exercise, viral infections, and tobacco smoke.2,3
What causes allergic asthma?
Allergens cause a reaction when your body thinks they are harmful. Your immune system tries to fight off the allergen by releasing a protein called immunoglobulin E (IgE). IgE then binds to immune cells. This causes immune cells to release inflammatory chemicals into the body. This leads to airway inflammation and symptoms of asthma.3,4
We do not yet know why some people have allergic asthma. Certain people are susceptible to producing high levels of IgE during an immune response. This tendency is called atopy. Atopic conditions include atopic dermatitis (eczema), allergic rhinitis, and allergic asthma.2
Atopic conditions like allergic asthma often run in families. This means genetic risk factors are likely involved with allergic asthma. Plus, some people with allergic asthma have other atopic conditions.2
Development of atopic conditions often progresses in a pattern. Many people develop eczema first, then food allergies, then hay fever, and finally asthma. This is called the "atopic march."3,5
How is it diagnosed?
Doctors diagnose allergic asthma based on symptoms, skin or blood tests, and spirometry. Spirometry is a type of breathing test. It measures how much air you can breathe in and out of your lungs. Test results that may suggest you have allergic asthma include:6
- High levels of exhaled nitric oxide
- High levels of white blood cells called eosinophils
- Positive skin prick allergy tests
- Positive specific IgE blood tests
How is it treated?
Treatment for allergic asthma usually involves inhaled steroids. These help manage and control asthma symptoms long-term. Your doctor may suggest other asthma drugs if inhaled steroids are not enough. This may include long-acting beta-agonist (LABAs) or leukotriene agonist drugs.6
Treatment may also include lifestyle changes to reduce your exposure to allergens. Talk to your doctor about changing your home environment to limit exposure. For example, keeping your home clean and dry can help reduce dust mites and cockroaches.7
Some people may benefit from allergy shots. These are also called allergen immunotherapy. These shots slowly expose your body to increasing doses of a particular allergen. This may help your body develop immunity or tolerance to the allergen.6