Do Allergies Cause Asthma?

Allergies don't cause asthma. But kids who have allergies or have family members who have allergies are more likely to get asthma than those who don't.

And when kids already have asthma, an allergic reaction can sometimes bring on their asthma symptoms.

How Do Allergies Bring on Asthma Symptoms?

When someone has an allergy, their immune system mistakenly reacts to something — known as an allergen — like it's an invader. Common allergens include dust mites, mold, pollen, and animal dander. To fight off the “invader," the immune system makes antibodies called immunoglobulin E (IgE). This causes certain cells to release chemicals into the bloodstream that are meant to protect the body. One of these is histamine. Histamine causes symptoms in the eyes, nose, throat, skin, and lungs.

When the airways are affected, it can trigger symptoms of asthma (like coughing, , or trouble breathing). This is why allergens that bring on asthma symptoms are also known as “triggers." The IgE antibodies can stay in the bloodstream for a long time, even after the symptoms are gone. So whenever the person comes into contact with the allergen, the asthma symptoms can quickly come back. Because of that, allergies can make it hard for some people to keep their asthma under control.

Do Allergies Affect a Child's Asthma?

Not everyone who has allergies will also have asthma. And not all cases of asthma are related to allergies. But if your child's asthma isn't under control, find out if allergies are making it worse. Talk to your doctor, who may refer your child to an allergist for testing.

If it turns out that your child's asthma is triggered by certain allergens, you'll want to limit your child's exposure to them. This can go a long way toward relieving asthma symptoms.

The doctor or allergist may recommend allergy medicine or allergy shots if your child can't avoid an allergen.