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What Is Atopy?

Medically Reviewed by Stephanie S. Gardner, MD on April 02, 2021

Atopy is a problem with your immune system that makes you more likely to develop allergic diseases. Your genes cause this problem.

When you have atopy, your immune system is more sensitive to common allergic triggers that you breathe in or eat. So you have a stronger-than-normal reaction to these allergens, such as dust, pollen, peanuts, or shellfish. If you have allergies or asthma, there’s a chance atopy is behind it.

What Happens in Atopy

When you have atopy and an allergen enters your body -- through your skin, airways, or mouth -- your immune system overreacts. It treats allergens like dangerous germs and makes germ-fighting antibodies called immunoglobulin E (IgE). These proteins make certain cells release chemicals that cause allergy symptoms in your nose, throat, and lungs, or on your skin.

What Causes Atopy?

Genes that you inherited from your parents make your immune system overreact. Immune cells produce too much IgE in response to normally harmless substances in your environment, which your doctor calls your triggers.

Researchers believe that many genes can cause atopy. About 80% of people with atopy have other family members with allergic diseases.

Conditions Related to Atopy

Atopy makes you more likely to have allergic conditions like these:

Asthma. This condition inflames your airways and tightens the muscles around them. This makes it harder to breathe. Allergens can trigger asthma attacks and cause symptoms like wheezing, shortness of breath, chest tightness, and coughing. Inhaled asthma medications open up narrowed airways and help you breathe more easily.

Allergic rhinitis. Also called “hay fever,” allergic rhinitis happens when your immune system mistakes harmless substances like pollen or pet dander for something dangerous. It releases chemicals that cause runny nose, itchy eyes, and other allergy symptoms. Medications, allergy shots, and avoiding triggers can help you manage allergic rhinitis.

Eczema. This condition, also known as atopic dermatitis, causes itchy, dry, red, and inflamed skin. It often happens inside the elbows, on the backs of the knees, and on the face and scalp. Your skin can flare up in response to allergic triggers such as soap or detergent. Half of people with eczema also have asthma or allergic rhinitis. Anti-inflammatory creams and moisturizers and avoiding your triggers can help you control flares.

Other allergic conditions also linked to atopy include:

Talking to Your Doctor About Atopy

Visit an allergy specialist if you have allergy symptoms like watery eyes, runny nose, wheezing, or hives and a family history of allergies or asthma. Your doctor will ask about your personal and family history and your symptoms. You may get blood or skin tests to help find your triggers. Then you and your doctor can come up with a treatment plan to help manage your allergy or asthma symptoms.

Show Sources

SOURCES:

American Academy of Allergy Asthma & Immunology: “Asthma Overview,” “Atopy Defined,” “Eczema (Atopic Dermatitis) Overview,” “Immunoglobulin E (IgE) Defined,” “Rhinitis (Hay Fever) Overview.”

JAMA Pediatrics: “Atopic Diseases in Children.”

Mayo Clinic: “Atopic dermatitis (eczema).”

StatPearls: “Atopy.”

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