What Happens

The first time you eat a food that triggers an allergic reaction, your body's immune system recognizes the food as a foreign substance (allergen). Your body reacts by developing antibodies against the food. When you eat the offending food again, the antibodies attack the allergen, releasing histamine and other chemicals that cause the symptoms of an allergic reaction.

To learn more, see the Symptoms and Treatment Overview sections of this topic.

What Increases Your Risk

You have a greater chance of developing food allergies if you:

• Have a family history of allergy. If both of your parents have allergies, you are more likely to have allergies.
• Have another allergic condition such as atopic dermatitis or asthma.
• Are young. Infants and children have more food allergies than adults.
• Have a medical condition that makes it easier for allergens to pass through the walls of the stomach and intestines and enter the bloodstream. These conditions include gastrointestinal disease, malnutrition, prematurity, and diseases that impair the immune system, such as eosinophilic esophagitis (EoE).

You have a greater risk for a life-threatening allergic reaction (anaphylaxis) from food allergy if you:

• Have asthma.
• Develop allergy symptoms within minutes of eating the food.

If you or your child has a severe food allergy, always carry an allergy kit and know how to use it. You should also wear a medical alert bracelet at all times. Being prepared to immediately deal with a severe allergic reaction reduces the risk of death.