What Is an Allergic Reaction?

Some people sneeze like crazy. Others get itchy hives or watery eyes. But whatever the reaction, it boils down to one thing: allergies.

If you have allergies, you have lots of company. As many as 30% of U.S. adults and 40% of children are in the same boat as you.

While your problem may seem to start in the nose or the eyes, allergies actually come from an immune system run wild.

Learning why these reactions happen can help you keep things under control and feeling better.

Why Allergic Reactions Happen

Your immune system has an important job: to defend your body from invaders such as bacteria and viruses that mean you harm.

But when it makes war on substances it shouldn’t, that’s an allergy.

Peanuts, eggs, or pollen, for example, can trigger reactions. They are called allergens.

During a reaction, your immune system releases antibodies. These are proteins that deliver a message to cells: Stop that substance! The cells then send out histamine, which causes blood vessels to expand, and other chemicals, and these trigger the allergy symptoms.

These antibodies are singled-minded. Each one targets only one type of allergen. That explains why someone might be allergic to peanuts but not to eggs.

You can come into contact with allergens in many ways: through the skin, eyes, nose, mouth, or stomach. This can cause your sinuses to clog up, inflame your skin, make it harder to breathe, or cause stomach problems.

What Things Most Often Cause an Attack?

Why do some people have such bad allergies and others don’t? Experts don’t have all the answers, but they say family history is important.

Some common allergens include:

● Animal dander

Bee stings

● Certain medications such as penicillin

Dust mites

● Foods -- particularly peanuts, tree nuts, fish, shellfish, eggs, milk, wheat, and soy

Insect bites

● Latex or other materials you touch

Mold

● Plants and pollens

The Symptoms, From Itchy Eyes to Sneezing

Your allergy attacks might range from mild and annoying to more severe and even life-threatening. It all depends on the way your body reacts and how much of the allergen got into your system.

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If your allergy is severe, you may have a serious reaction called anaphylaxis. Some cases could be life-threatening and need urgent attention.

Here are some common types of allergies:

Hay fever: Also known as allergic rhinitis, it can cause:

Food allergies : You may feel tingling in your mouth. Your tongue, lips, throat, or face might swell up. Or you could get hives. In the worst cases, you might have anaphylaxis and will need medical help right away.

Eczema: Also known as atopic dermatitis, it is a skin condition. You might have it if you have itching, redness, and peeling or flaking.

Medications: If you’re allergic to a certain drug, you may get a rash, facial swelling, or hives. You could find yourself wheezing. In severe cases, you may develop anaphylaxis.

Stings: If you’re allergic to bees or other insects you may get:

  • A large area of swelling, known as edema, at the site of the sting
  • Itching or hives all over your body
  • Shortness of breath, wheezing, chest tightness, or a cough

As with some other allergies, such as food and medication, a severe reaction to a sting can lead to anaphylaxis.

Anaphylaxis: What Is It and How to Get Help

Most people with allergies get only mild to moderate symptoms, but bad cases can lead to anaphylaxis.

It’s a serious situation and can put your body into shock. Food, medications, insect bites, or latex are the most likely causes.

A second anaphylactic episode can happen up to 12 hours after the first one.

The symptoms of anaphylaxis can come on suddenly.

They can quickly go from a mild rash or runny nose to serious problems such as a hard time breathing, tightness in the throat, hives or swelling, nausea or vomiting, and fainting or dizziness. Some people can get a rapid pulse or their heart will stop beating.

If you’ve had previous attacks or know you are at risk for anaphylaxis, your doctor might prescribe medicine that you can give yourself, or that someone else can give you. Adrenaclick, Auvi-Q, and EpiPen are injection devices loaded with this medicine.

Carry this with you always and be aware of your allergy triggers.

Call 911 and go straight to an emergency room at the first sign of trouble, even if you have used the injection device. Go even if you are starting to feel better, in case you have a delayed reaction.

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How Can I Get Relief?

You can find treatment options for mild to moderate allergic reactions. Antihistamines and decongestants can help treat certain symptoms, as can nasal sprays.

If you have an allergic-type asthma, your doctor might also prescribe an inhaler to ease attacks. Or she may inject a special antibody to manage symptoms.

If you don’t get enough relief by avoiding your allergens and using medications, your doctor may want to give you allergy shots. This type of treatment is called immunotherapy, and it can be effective for hay fever and allergic asthma.

Another type of immunotherapy involves drops that dissolve under your tongue.

For your sinuses, an over-the-counter medication might ease your symptoms.

WebMD Medical Reference Reviewed by Laura J. Martin, MD on 4/, 016

Sources

SOURCES:

Asthma and Allergy Foundation of America: “Allergy Facts and Figures.”

American Academy of Allergy, Asthma & Immunology: “Allergic Reactions,” “Anaphylaxis.”

University of Maryland Medical Center: “Allergic Reactions.”

Mayo Clinic: “Allergies.”

Cleveland Clinic: “Allergy Overview.”

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