March 2007 QUIZ OF THE MONTH . . . There is still uncertainty and some debate about aspects of food allergy (FA). Which of the statements enclosed below are true or false? 1. Allergy to milk in childhood is more likely to be outgrown than is allergy to peanut. 2. An allergic reaction to conformational epitopes of milk in childhood is more likely to persist into adolescence than is an allergy to a linear epitope in milk, 3. The level of IgE antibodies against a food detected by a RAST type can help predict the likelihood that the FA will persist past childhood. 4. The immunologic cross-reactivity between certain pollens and foods is not pathogenically relevant in humans. 5. Cooking a food will almost always render it non-allergenic. Discussion It is now known that allergies to foods can vary from child to child in both severity and persistence. Although one cannot predict with certainty whether an individual child with FA will outgrow that allergy, several characteristics of the FA will help estimate the likelihood of a FA persisting into adolescence and possibly beyond. Allergies to some foods such as peanuts, tree nuts and fish are more likely to persist into adulthood than are allergies to eggs and cow's milk. If an individual has IgE antibodies against multiple allergenic epitopes within a particular food, the clinical allergy is more likely to persist past childhood. Higher levels of anti-food IgE antibodies are also somewhat predictive of more likely persistent FA. The cross-reactivity between certain pollens and foods is clinically important. For example, children who are allergic to birch tree pollen are at increased risk for manifesting allergic reactions to ingested apples or hazelnut. Only some food allergens are heat-labile. The other allergens persist in well- cooked foods. Indeed, some individuals develop allergic respiratory symptoms when inhaling the vapors emitted during cooking of food to which they are allergic. References J Allergy Clin Immunol 2006;117:S470-5 Medical J of Australia 2006;185:394-400 Allergy 2003;58:435-8 Think you have the answers? Click here to find out if you're right! Please tell us what you think of this site. © Copyright 1997-2007 American Academy of Allergy, Asthma & Immunology All rights reserved