Food Allergy
Source: MedlinePlus Health Topics, U.S. National Library of Medicine
What is a food allergy? A food allergy is an abnormal immune system reaction to certain foods. Your immune system normally protects you from germs. But if you have a food allergy, your immune system mistakenly reacts to certain foods as if they were harmful. This reaction is usually mild. But in some cases, it can be serious or even life-threatening. A food intolerance is different than a food allergy. If you have a food intolerance, you also have symptoms when you eat that food. But these are typically just digestive symptoms such as bloating and gas . Also, an intolerance is not an immune system reaction. Most food allergies are caused by: Cow's milk Chicken eggs Crustacean shellfish, such as shrimp, crab, lobster, and crayfish Fish Peanuts Sesame Soy Tree nuts, such as almonds, walnuts, pecans Wheat People with a food allergy may be allergic to more than one type of food. Who is more likely to develop a food allergy? Both children and adults can have food allergies. Some children will outgrow their food allergies. And sometimes people can develop food allergies as adult. Certain factors can make you more likely to have a food allergy. They include: Having eczema , a disease that causes inflammation, redness, and irritation of the skin. Your immune system also plays a role in eczema. Having asthma or other allergies , such as hay fever . Your genes. Certain genes may influence the development of food allergies. And you are more likely to have food allergies if someone in your family has allergies, asthma, or eczema. What are the symptoms of food allergies? If you are allergic to a food you have eaten, you may have a variety of symptoms. These symptoms are not always the same for every person. And the symptoms that you get each time you eat the food may not always be the same. For example, your symptoms may sometimes depend on how much of the food you ate. Food allergy symptoms usually start within a few minutes to two hours after you eat that food. They may includ