AllergyAllergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note that food intolerances and food poisoning are separate conditions. Common allergens include pollen and certain foods.
Food allergyA food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. This typically occurs within minutes to several hours of exposure. When the symptoms are severe, it is known as anaphylaxis. A food intolerance and food poisoning are separate conditions, not due to an immune response.
Soy allergySoy allergy is a type of food allergy. It is a hypersensitivity to ingesting compounds in soy (Glycine max), causing an overreaction of the immune system, typically with physical symptoms, such as gastrointestinal discomfort, respiratory distress, or a skin reaction. Soy is among the eight most common foods inducing allergic reactions in children and adults. It has a prevalence of about 0.3% in the general population. Soy allergy is usually treated with an exclusion diet and vigilant avoidance of foods that may contain soy ingredients.
Milk allergyMilk allergy is an adverse immune reaction to one or more proteins in cow's milk. Symptoms may take hours to days to manifest, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon. However, rapid anaphylaxis is possible, a potentially life-threatening condition that requires treatment with epinephrine, among other measures. In the United States, 90% of allergic responses to foods are caused by eight foods, and cow's milk is the most common.
Peanut allergyPeanut allergy is a type of food allergy to peanuts. It is different from tree nut allergies, because peanuts are legumes and not true nuts. Physical symptoms of allergic reaction can include itchiness, hives, swelling, eczema, sneezing, asthma attack, abdominal pain, drop in blood pressure, diarrhea, and cardiac arrest. Anaphylaxis may occur. Those with a history of asthma are more likely to be severely affected. It is due to a type I hypersensitivity reaction of the immune system in susceptible individuals.
Egg allergyEgg allergy is an immune hypersensitivity to proteins found in chicken eggs, and possibly goose, duck, or turkey eggs. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. In the United States, 90% of allergic responses to foods are caused by cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soybeans.
AllergenAn allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms, an allergen is an antigen that is capable of stimulating a type-I hypersensitivity reaction in atopic individuals through immunoglobulin E (IgE) responses. Most humans mount significant Immunoglobulin E responses only as a defense against parasitic infections.
Oral allergy syndromeOral allergy syndrome (OAS) or pollen-food allergy is a type of food allergy classified by a cluster of allergic reactions in the mouth and throat in response to eating certain (usually fresh) fruits, nuts, and vegetables. It typically develops in adults with hay fever. OAS is not a separate food allergy, but rather represents cross-reactivity between distant remnants of tree or weed pollen still found in certain fruits and vegetables. Therefore, OAS is only seen in people with seasonal pollen allergies, and mostly people who are allergic to tree pollen.
AntibodyAn antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision.
Wheat allergyWheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.
