Tree nut allergy

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 almonds, Brazil nuts, cashews, chestnuts, filberts/hazelnuts, macadamia nuts, pecans, pistachios, shea nuts and walnuts.

Management is by avoiding eating the causal nuts or foods that contain them among their ingredients, and a prompt treatment if there is an accidental ingestion. Total avoidance is complicated because the declaration of the presence of trace amounts of allergens in foods is not mandatory in every country.

Tree nut allergies are distinct from peanut allergy, as peanuts are legumes, whereas a tree nut is a hard-shelled nut.