Tree nut allergy

Tree nut allergy, a hypersensitivity to dietary substances from tree nuts and edible tree seeds causing an overreaction of the immune system, may lead to severe physical symptoms. Tree nuts include, but are not limited to, Brazil nuts (are seeds), cashews (are seeds), chestnuts, filberts/hazelnuts, macadamia nuts, pecans, pistachios (are seeds), pine nuts (are seeds), and walnuts (are seeds).