Food allergy occurs in 6% of the population less than 5 years of age and in 3.5-4% of the adult population. Food allergies most often start in infants and young children but they can occur at any age. Common food allergens in infants/children include milk, egg, and peanut and in adults shellfish, fish, and tree nuts.
Symptoms from food allergy may occur immediately and/or up to several hours after the ingestion of a food. Symptoms include hives, swelling, wheezing, cough, choking, immediate vomiting, and a runny nose/sneezing. It is very rare for isolated symptoms in the nose or lungs to occur with a food allergy.
Occasionally, there may only be isolated itching of the mouth or throat with the ingestion of raw fruits and/or vegetables, a condition called Oral Allergy Syndrome or Food-Pollen Syndrome. This occurs because of a cross-reaction between the allergens in pollens and foods.
Diagnosing a food allergy requires a careful history, physical exam, food skin testing and/or blood allergy testing, and, in some cases, an oral food challenge. For a food challenge, you will be asked to bring the food into the office so it can be administered starting with a very low dose and then building up over several doses in a controlled safe environment. Your BVAAC board-certified allergist will take all of these factors into account when diagnosing your food allergy. It is possible to have a positive allergy test to a food and yet not react to the food when eaten. Always speak to your BVAAC board-certified allergist before giving any food that might have the potential to cause an allergic reaction!
There is no cure for food allergies. Some foods, such as milk and egg, will probably be outgrown over time. Others, such as peanuts, tree nuts, and shellfish, may persist indefinitely. The management of food allergy usually consists of a combination of training in avoidance, symptom recognition, use of injected epinephrine in conjunction with a food allergy action plan in the event of a significant food allergy reaction, and in some cases an in-office food challenge. Extensive education in regards to avoidance, label reading, symptom recognition, knowledge of cross-reacting allergens, utilization of epinephrine, etc. is absolutely necessary. Because a positive allergy test dose not always mean that there will be symptoms with food ingestion, an in-office food challenge in a safe environment can be very helpful. In fact, 3/4 of children with milk or egg allergy could pass a baked egg/milk milk muffin challenge in the office. Their future diet could be broadened, and their is evidence that they will outgrow the milk and/or egg allergy faster.
There is a a tremendous amount of ongoing research in food allergy. The NIH now recommends that all young children around 6 months of age and older with egg allergy or atopic dermatitis be tested for peanut allergy. If the test is negative, peanut should be cautiously introduced into their diet to prevent peanut allergy from developing. A recent study called the LEAP (Learning Early About Peanut) study showed that this early peanut introduction can reduce the chances of developing peanut allergy by 80%. Oral Immunotherapy (OIT), as well as a peanut patch, are curently being studied as a way to provide protection from peanut allergy, but neither of these are currently approved by the FDA, and the experts in the field feel that the risks do not outweigh benefits at this time. Toward the end of this year or in early 2019, a type of low-dose OIT (AR 101), as well as a peanut patch will be FDA approved. Stay tuned. Both of there treatments will be available here at Boise Valley Asthma and Allergy Clinic as soon after FDA approval as possible.
