The immune system protects your body against foreign substances by starting a response. This immune response releases antibodies. The antibodies protect you against the threat. Sometimes the immune system attacks a substance that should be harmless, like food or pollen, and this causes allergies.

An allergen is something in your surroundings that causes your body to react. In people who don’t have the allergy, the allergen is harmless. If you are allergic, symptoms often affect your eyes, nose, throat, mouth, and skin.

The cells in your body release histamine in response to an injury, allergen or inflammation. Histamine causes the redness, itching and swelling linked to allergies.

Other symptoms of anaphylaxis include hives, swelling, vomiting, and diarrhea. Some people will have all of these symptoms. Others may have only one or two. Anaphylaxis is life-threatening. Call 911 or get emergency help right away.

Shellfish include shrimp, lobsters, and oysters. An allergic reaction to shellfish, eggs, peanuts, or wheat may be severe or even life-threatening. Any allergic reaction to celery is often mild. Food allergies to celery are less common and may cause only mild symptoms. Celery root (celeriac) often causes more of a problem than celery.

A Medic Alert bracelet lets emergency responders know that you have an allergy if you aren’t able to tell them. Knowing the kind of allergy you have helps responders know right away how to start treatment.

All current childhood vaccines are safe for children with an egg allergy. It's important for children to stay up to date on their vaccines.

The mites live where people spend a long period of time. Washing sheets and blankets in hot water will reduce dust mites. So will using mattress and pillow covers.