A detailed patient history will hopefully begin to uncover the type of food allergy your patient has.1,3
A patient’s symptom presentation can help you begin to get an idea of whether the reaction they are reporting is immune-mediated or non-immune-mediated.3 The latter involves general intolerances to specific types of foods or ingredients. The former involves certain cells or antibodies.11
Adverse Food Reaction:
Non-immune Mediated
Adverse Food Reaction:
Immune Mediated
Diagnosis, followed by counseling and advice based on test results, can help to reduce the incidence of adverse reactions and the unnecessary exclusion of foods that should be eaten as part of a normal, healthy diet.1,3
Diagnosing food allergy starts with a physical examination and, of critical importance, a food allergy-focused patient history.2,3
Goals of a patient history also include the identification of the types or specific foods that may be responsible for the allergy. Although more than 170 foods have been identified as triggers of food allergy, eight allergen groups account for 90 percent of food allergies.2,13
Milk, egg, and peanut contribute to the highest number of allergic reactions in children—while peanuts, tree nuts, and seafood are the top contributing allergens in adults and teens.2,13
The information you gather in this history can then be used to guide testing decisions and interpretation of results. This systematic approach can help determine whether the patient-reported history of food allergies and data from laboratory or skin testing are sufficient for diagnosis. If they are not, an oral food challenge (OFC) may be considered to assist in the correct identification of the offending allergens.
Pollen food allergy syndrome (PFAS), also known as oral allergy syndrome (OAS), is an allergic reaction that typically occurs after a patient who is sensitive to pollen eats certain foods.10 PFAS is possibly the most common food allergy in adults, with up to 60 percent of patients allergic to pollen being affected.10
Symptoms of PFAS happen when the food the person is allergic to touches the oral mucosa, lips, tongue, or throat. These symptoms of OAS appear within minutes of eating a raw form of the food but can last for hours. In the majority of cases, the responsible allergens are rapidly denatured by cooking and digestion, though certain patients can still present with systemic reactions.10
On average, patients with PFAS will have four foods that will lead to PFAS symptoms. Foods that trigger symptoms in up to 60 percent of patients sensitized to pollen include raw fruits, vegetables, nuts, or grains.10
Almond, apple, apricot, carrot, celery, cherry, chestnut, chicory, date palm, fennel, fig, grape, hazelnut, jackfruit, kiwi, melon, orange, nectarine, parsley, parsnip, peach, peanut, pistachio, pear, plum, potato, prune, spinach, walnut, watermelon
Apple, carrot, celery, chamomile, chestnut, currant, date palm, eggplant, fig, grape, kiwi, melon, orange, nectarine, peach, pistachio, tomato, watermelon
Aniseed, apple, avocado, caraway seed, carrot, celery, chamomile, coriander, fennel, mango, mustard, parsley, peach, peppers, sunflower, watermelon
Apple, banana, cantaloupe, carrot, celery, chamomile, coriander, cucumber, dandelion, fennel, honeydew, kiwi, melon, peach, peppers, watermelon, zucchini
During your detailed patient history, you will likely uncover several symptoms that could be attributed to food allergies. Symptoms range from mild to severe and, in some cases, can be fatal.1 For example, patients with asthma face an increased risk for severe exacerbations if they also have food allergies.4 Severe allergic reactions in children, such as anaphylaxis, were reported to have increased up to sevenfold between 1992 and 2012, but have since stabilized in the last five years.5
Food allergies are a growing problem among infants and children. Approximately 40 percent of infants and young children with moderate to severe eczema suffer from food allergies,1 with eggs, cow's milk, soy, and wheat accounting for the majority of allergenic foods.1,2,7
Fortunately, the majority of children with an egg or milk allergy will outgrow it by age 5.2 In the meantime, though, children allergic to those and other foods often experience a diminished quality of life. This is often due to:8,9
For these reasons, early identification and avoidance of the allergenic foods is critical. Furthermore, there is a known link between food allergies and other disease: About 40 percent to 60 percent of children with an allergy to eggs or milk will develop asthma, and 30 percent to 55 percent will develop allergic rhinitis.2