The Botany of Nuts Allergies

Peanuts & Tree Nuts in Top 10 Food Allergies for Children / Adults

Jun 16, 2007

The most common food allergies in children are egg, milk, peanut, soy, fish, shellfish, and tree nuts. Some people are allergic to food items in the same plant family.

For the person who gets a rash that looks like poison ivy if he eats cashews or mangos, it is interesting to note that Cashew Nuts, Poison Ivy, Pistachio Nuts and Mangos are all in the same plant family. That means cashews are more closely related to mangos than to other nuts like, almonds.

Tree Nut Families

Almonds are in the plum family, along with peaches, apricots, cherries, wild cherries, nectarines, plums, prunes.

Chestnuts (Beechnut family), Macadamia nut (Protea Family), filberts and hazelnuts from the Birch family and brazil nuts are all considered tree nuts. Nuts from the walnut family are also common allergens for people with tree nut sensitivity. They include black walnuts, butternuts, pecans, hickory nuts and English walnuts.

Pinion nuts or pine nuts from the pine family, nutmeg, lychee nuts and coconut are not usually included as a tree nut for people with tree nut allergies. Water chestnuts are not a nut, they are a vegetable, part of the sedge family.

Maple Syrup

People with tree nut allergies can sometimes react to maple sugar but it is hard to know if they are reacting because it is a nut producing tree or because the maple sap plugs are sometimes treated with or contaminated with formaldehyde.

Peanuts

People with peanut allergy are not necessarily allergic to tree nuts although they are usually counseled to avoid all nuts due to the possibility of cross-contamination in processing or packaging. Peanuts are part of the legume (bean) family and grown in the ground, not on a tree.

Some people’s immune system reacts to both peanuts and to tree nuts. According to de Leon, in "IgE cross-reactivity between the major peanut allergen Ara h 2 and tree nut allergens", peanut and tree nut allergies are bad because "allergy to peanut and tree nuts is characterized by a high frequency of life-threatening anaphylactic reactions and typically lifelong persistence. Although peanut is the most common cause of nut allergy, peanut allergic patients are frequently also sensitive to tree nuts." In the study de Leon, found that peanuts, almonds and Brazil nuts share a common immune system irritant called, Ara h 2 , which cause an IgE immune system reaction. This is the part of the immune system that when triggered leads to an anaphylactic shock reaction.

Peanut oil made in heat treated processes are generally regarded as safe for people with peanut allergy (no guarantees though). However, cold pressed peanut oil, commonly used in Chinese and Thai cooking are not typically safe for those with peanut allergy.

Anaphylaxic Shock

In an article entitled, "Anaphylaxis Facts and Fallacies", Paul Brand notes, "the most common causes of anaphylaxis are food allergens, such as peanut and tree nuts, insect stings, and drugs, in particular antibiotics. Many patients with peanut or tree nut allergy show only mild allergic symptoms; only a minority develop anaphylaxis upon exposure."

In someone sensitive to nuts, recognizing the signs of anaphylactic shock can get them to life saving treatment sooner. Anaphylactic shock may begin with any of the following symptoms: difficulty breathing; wheezing, changes in consciousness (including confusion, light-headedness, or stupor), rapid swelling throughout the body, hives, blue skin [lack of oxygen], severe abdominal pain, nausea, or diarrhea.

The copyright of the article The Botany of Nuts Allergies in Food Allergies is owned by Kimberly Burnham. Permission to republish The Botany of Nuts Allergies in print or online must be granted by the author in writing.