Allergen-specific immunotherapy is a type of treatment in which a patient is given increasing doses of an allergen—for example, milk, egg, or peanut allergen—with the goal of inducing immune tolerance (the ability of the immune system to ignore the presence of one or more food protein allergens while remaining responsive to unrelated proteins).
Allergic contact dermatitis (ACD) is a form of eczema caused by an allergic reaction to food additives or molecules that occur naturally in foods such as mango. The allergic reaction involves immune cells but not IgE antibodies. Symptoms include itching, redness, swelling, and small raised areas on the skin that may or may not contain luid.
Allergic proctocolitis (AP) is a disorder that occurs in infants who seem healthy but have visible specks or streaks of blood mixed with mucus in their stool. Because there are no laboratory tests to diagnose food-induced AP, a healthcare professional must rely on a medical history showing that certain foods cause symptoms to occur. Many infants have AP while being breast-fed, probably because the mother’s milk contains food proteins from her diet that cause an allergic reaction in the infant.
Anaphylaxis is a serious allergic reaction that involves more than one body system (for example, skin and respiratory tract and/or gastrointestinal tract), begins very rapidly, and may cause death.
Angioedema is swelling due to luid collecting under the skin, in the abdominal organs, or in the upper airway (nose, back of the throat, voicebox). It often occurs with hives and, if caused by food, is typically IgE-mediated. When the upper airway is involved, swelling in the voicebox is an emergency requiring immediate medical attention. Acute angioedema is a common feature of anaphylaxis.
Contact urticaria (hives) occurs when the skin comes in contact with an allergen. The hives can be local or widespread. They are caused by antibodies interacting with allergen proteins or from the direct release of histamine, a molecule involved in allergy.
Corticosteroids are a class of drugs similar to the natural hormone cortisone. These drugs are used to treat inlammatory diseases, such as allergies and asthma.
Cross-reactive foods are foods that are seen as similar to allergenic foods by the immune system. An antibody that reacts with the allergenic food also reacts with the cross-reactive food. For example, a person who is allergic to shrimp also may be allergic to lobster, because shrimp and lobster are closely related foods. In this case, lobster would be a cross-reactive food.
Eczema (atopic dermatitis, atopic eczema) is a disease of the skin. Symptoms include scaly, itchy rashes and blistering, weeping, or peeling of the skin. The causes of the disease are unclear. There may be a problem in the skin’s ability to maintain an effective barrier against environmental factors, such as irritants, microbes, and allergens. A person who has a biological parent or sibling with a history of allergy and eczema is at risk for developing food allergy.
Enterocolitis is an inflammation of the colon and small intestine.
Enteropathy is a disease of the intestine.
Eosinophilic esophagitis (EoE) is a disorder associated with food allergy, but how it is related is unclear. It occurs when types of immune cells called eosinophils collect in the esophagus. Both IgE- and non-IgE-mediated mechanisms appear to be involved in EoE.
Epinephrine (adrenaline) is a hormone that increases heart rate, tightens the blood vessels, and opens the airways. Epinephrine is the best treatment for anaphylaxis.
Exercise-induced anaphylaxis is a type of severe, whole-body allergic reaction that occurs during physical activity. Food is the trigger in about one-third of patients who have experienced exercise-induced anaphylaxis. This reaction is likely to recur in patients.
Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated disorder that usually occurs in young infants. Symptoms include chronic vomiting, diarrhea, and failure to gain weight or height. When the allergenic food is removed from the infant’s diet, symptoms disappear. Milk and soy protein are the most common causes, but some studies report reactions to rice, oat, or other cereal grains. A similar condition also has been reported in adults, most often related to eating crustacean shellfish.
Immunotherapy with cross-reactive allergens is a type of treatment in which a patient is given increasing doses of an allergen to induce tolerance to a similar allergen that is causing a reaction.
Noncontact food allergy develops as a result of the food allergen being ingested. Specific IgE antibodies to the food are only made after eating the food, not after simply touching the food.
Systemic contact dermatitis is a rare disorder with symptoms that include eczema, fever, headache, and stuffy nose. To develop systemic contact dermatitis, a person first develops specific IgE antibodies to the allergen through contact with the skin. If the person subsequently swallows the allergen or is exposed to it though a skin cut or puncture, symptoms develop.