symptoms when an affected person eats certain fruits, vegetables, and nuts. Some individuals may only show allergy to one particular food, and others may show an allergic response to many foods. Individuals with an allergy to tree pollen may develop OAS to a variety of foods. While the tree pollen allergy has been worked out, the grass pollen is not well understood. Furthermore, some individuals have severe reactions to certain fruits and vegetables that do not fall into any particular allergy category. When tropical foods initiate OAS, allergy to latex may be the underlying cause. Because the allergenic proteins associated with OAS are usually destroyed by cooking, most reactions are caused by eating raw foods. The main exceptions to this are celery and nuts, which may cause reactions even after being cooked. Cross reactions Allergies to a specific pollen are usually associated with OAS reactions to other certain foods. For instance, an allergy to ragweed is associated with OAS reactions to banana, watermelon, cantaloupe, honeydew, zucchini, and cucumber. This does not mean that everyone with an allergy to ragweed will experience adverse effects from all or even any of these foods. Reactions may be associated with one type of food, with new reactions to other foods developing later. However, reaction to one or more foods in any given category does not necessarily mean a person is allergic to all foods in that group. Alder pollen: almonds, apples, celery, cherries, hazel nuts, peaches, pears, parsley, raspberry, strawberry Birch pollen: apples, peach, pear, cherry. carrots, celery, , chicory, coriander, fennel, fig, hazel nuts, kiwifruit, nectarines, parsley, parsnips, peaches, pears, peppers, plums, potatoes, prunes, soy, strawberries, wheat, jackfruit; Potential: walnuts Grass pollen: fig, melons, tomatoes, oranges, celery, peach Mugwort pollen: carrots, celery, and mustard Ragweed pollen: banana and melons ( honeydew, watermelon,cantaloupe), cucumber, green pepper, paprika, sunflower seeds/oil, zucchini, echinacea, artichoke, dandelions, honey Diagnosis The person typically already has a history of atopy and an atopic family history. Eczema, otolaryngeal symptoms of hay fever or asthma will often dominate leading to the food allergy being unsuspected. Often well-cooked, canned, pasteurized, or frozen food offenders cause little to no reaction due to denaturation of the cross-reacting proteins, causing delay and confusion in diagnosis as the symptoms are elicited only to the raw or fully ripened fresh foods. Correct diagnosis of the allergen types involved is critical. Those with OAS may be allergic to more