What medical conditions are related to food sensitivity?

Eczema, also called atopic dermatitis, is a common condition characterized by dry, inflamed, itchy skin. Eosinophilic esophagitis, or EoE, is a chronic condition that may be associated with food allergies. It is increasingly diagnosed in children and adults. EoE is characterized by the buildup of immune cells called eosinophils in the esophagus.

Food intolerance is a chemical reaction that some people have after eating or drinking certain foods; it's not an immune response. Food intolerance has been associated with asthma, chronic fatigue syndrome, and irritable bowel syndrome (IBS). It can be difficult to differentiate between the symptoms of food allergy and food intolerance. Symptoms caused by food allergy usually occur soon after eating the food.

While symptoms caused by food intolerance may be immediate, they can also take 12 to 24 hours to appear. Food intolerance reactions are usually related to the amount of food eaten. They may not occur until a certain amount (threshold level) of food is eaten, but this amount varies for each person. The symptoms of food allergy and intolerance can also be caused by other conditions, so it's important to see your doctor for a medical diagnosis.

Food allergy is an immune system reaction that occurs soon after eating a certain food. Even a small amount of the food that causes the allergy can cause signs and symptoms, such as digestive problems, hives, or inflammation of the respiratory tract. In some people, a food allergy can cause serious symptoms or even a life-threatening reaction known as anaphylaxis. Gluten is a protein found in grains, such as wheat, barley, and rye.

Some people are allergic to wheat, but that's not the same as a gluten allergy. Gluten allergy is a misleading term that is commonly confused with wheat allergy or sometimes celiac disease. There is no allergy to gluten, but there is a condition called celiac disease. Celiac disease is a digestive condition that can be serious if left undiagnosed or treated.

Celiac disease symptoms include severe diarrhea after eating gluten-containing products, rash, severe weight loss or lack of adequate weight gain, and abdominal pain. In young children, you may only see poor weight gain and you may not experience pain or other symptoms. The diagnosis of celiac disease can only be made by a board-certified gastroenterologist. It should also be done when the person eats foods with gluten, since the active treatment is to avoid it.

It is impossible to predict the severity of the next reaction, and all patients with food allergies should receive careful advice about the risk of anaphylaxis, a potentially fatal reaction that is treated with epinephrine (adrenaline). A skin reaction to a food tested does not necessarily mean that the person is allergic to that food, but the absence of a skin reaction means that an allergy to that food is unlikely to occur. The National Allergy StrategyExternal Link has developed a resource center to help with best practice procedures for managing food allergens. To prevent these allergies from developing, many parents avoid exposing their young children to these foods.

The next time you eat even the smallest amount of that food, the IgE antibodies will detect it and tell the immune system to release a chemical called histamine, as well as other chemicals, into the bloodstream. For some adults with food allergies, eating even a small amount of food can cause a severe and sudden reaction. For many years, doctors have advised against feeding young babies foods that often cause an allergic reaction (such as peanuts) as a way to prevent food allergies. NIAID is currently funding studies investigating the efficacy of diets to avoid foods and other experimental approaches to control EoE.

While allergies are often inherited, it's impossible to predict whether a child will inherit a food allergy from a parent or if their siblings will suffer from a similar condition. When you have a food allergy, your immune system misidentifies a specific food or food substance as harmful. If you have celiac disease and eat foods that contain gluten, an immune reaction occurs that damages the surface of the small intestine and causes the inability to absorb certain nutrients. Doctors can usually diagnose oral allergy syndrome when people who have a pollen allergy have allergic symptoms after eating certain foods.

The plan must provide instructions for preventing, recognizing, and controlling food allergies and must be available at school and during activities such as sporting events and field trips. Often, people who have both food allergies and EoE can avoid EoE symptoms by avoiding their allergen. Once you've been diagnosed with a food allergy, your allergist will prescribe an epinephrine autoinjector and teach you how to use it. For positive tests of foods you've never eaten but that are related to products you've had an allergic reaction to, the best way to determine if the food poses a danger is to perform an oral food test.