A tree nut allergy is a hypersensitivity to dietary substances from tree nuts and edible tree seeds causing an overreaction of the immune system which may lead to severe physical symptoms. Tree nuts include, but are not limited to, almonds, Brazil nuts, cashews, chestnuts, filberts/hazelnuts, macadamia nuts, pecans, pistachios, pine nuts, shea nuts and walnuts.
Tree nut allergies are distinct from peanut allergy, as peanuts are legumes, whereas a tree nut is a hard-shelled nut.
Video Tree nut allergy
Description
People with tree nut allergy are seldom allergic to just one type of nut, and are therefore usually advised to avoid all tree nuts, even though an individual may not be allergic to the nuts of all species of trees.
Someone allergic to walnuts or pecans may not have an allergy to cashews or pistachios, because the two groups are only distantly related and do not necessarily share related allergenic proteins. The severity of the allergy varies from person to person, and exposure can increase sensitization. For those with a milder form of the allergy, a reaction which makes the throat feel like cotton may occur. Subjects allergic to tree nut can experience asthma, skin rashes, itchy throat, swollen eyes. The most severe reaction can lead to anaphylaxis and sensitive subjects may need to carry with them at all times disposable adrenaline injectors prescribed by their GP. Less severe reaction can be dealt with by assuming antihistamines tablet. The raw nut protein usually causes a more severe reaction than the oil, and extra roasting or processing can reduce the allergic reaction. Those diagnosed with anaphylaxis will have a more immediate mast cell reaction and be required to avoid all exposure to any allergen-containing products or byproducts, regardless of processing, as they are prone to even greater sensitivity. An allergy test or food challenge may be performed at an allergy clinic to determine the exact allergens. New immunotherapy treatments are being developed for tree nut allergy.
This allergy tends to be lifelong; recent studies have shown that only about 9% of children outgrow their tree nut allergy.
Hazelnut has been used as a model tree nut in the study of tree nut allergies.
Maps Tree nut allergy
Prevention and treatment
Prevention involves an exclusion diet and vigilant avoidance of foods that may be contaminated with tree nuts, nut particles, or oils extracted from nuts. In the United States, the federal Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that any packaged food product that contains tree nuts as an ingredient must list the specific tree nut on the label. Foods that almost always contain tree nuts include pesto, marzipan, Nutella, baklava, pralines, nougat, gianduja, and turrĂ³n. Other common foods that may contain tree nuts include cereals, crackers, cookies, baked goods, candy, chocolates, energy/granola bars, flavored coffee, frozen desserts, marinades, barbecue sauces, and some cold cuts, such as mortadella. Tree nut oils (especially shea nut) are also sometimes used in lotions and soaps. Asian and African restaurants, ice cream parlors, and bakeries are considered high-risk for people with tree nut allergy due to the common use of nuts and the possibility of cross contamination.
See also
- Food allergy (has images of hives, skin prick test and patch test)
- List of allergens (food and non-food)
- Anaphylaxis
- Asthma
- Peanut allergy
Notes
References
External links
- Tree nut allergy at Food Allergy Initiative
- "Are Nut Bans Promoting Hysteria?" by Tana Parker-Pope at The New York Times (15 Dec 2008)
- Is Peanut Allergy Related to Tree Nut Allergies? at PeanutAllergy.com
Source of the article : Wikipedia