Food allergies affect over 3 million children in the United States. Milk is the most common food allergy, affecting approximately 2.5 percent of all children under the age of 3. Currently, there is no safe or effective treatment for food allergies. Patients must avoid all foods that contain their allergen (the food that causes their allergy). But researchers at Children’s Hospital Boston and the Stanford University School of Medicine are hoping to change that by developing a way to desensitize children so they will no longer be allergic to milk.
A food allergy is a response by the body’s immune system to something it perceives to be a threat. When someone who is allergic comes in contact with an allergen such as milk for the first time, his body produces an antibody called immunoglobulin E (IgE) which is targeted specifically at that allergen. The next time he drinks milk or eats anything that contains milk, the IgE antibodies trigger cells in the body to release the chemical histamine which causes the symptoms we associate with a food allergy reaction including:
• Itching or swelling in the mouth
• Stomach pain, vomiting, or diarrhea
• Hives on the skin
• Swelling in the airways and difficulty breathing
A severe food allergy can cause anaphylaxis, which is a life-threatening reaction that causes airways to close and blood pressure to drop and may result in death.
While some children outgrow their allergies to milk, some people continue to be allergic as adults and must strictly limit their diet to avoid milk products in order to ward off an allergic reaction. Previous efforts have been made to desensitize people with milk allergies by having them very gradually add milk to their diets in the hope their bodies would adjust. The Boston research team was the first to start the children in their study on doses of the drug omalizumab marketed by the company Genentech under the brand name Xolair. Omalizumab helps limit allergic reactions by binding with IgE antibodies before they encounter the milk protein they were created to react with. With less IgE able to send a signal that an allergen is present, the immune system response is reduced and the allergic reaction is limited.
In addition to the drug omalizumab, the researchers spent 10 weeks giving the children in the study increased amounts of milk each day. At the end of 10 weeks, most of the children were able to drink 8 to 12 ounces of milk a day with minimal or no allergic reaction. In more traditional approaches to food allergy, up to 20 percent of people who begin the process are forced to drop out due to unmanageable allergic reactions. For those who are able to continue, the process of desensitization lasts much longer than 10 weeks.
Dale Umetsu, MD, PhD, at Children's Hospital Boston said, “These children had significant milk allergy, and were unlikely to outgrow it without some type of treatment. While we recognize that larger trials are necessary, these results are very promising, and suggest that a rapid and safe method of food desensitization might be available for patients in the near future."
Thanks to this new desensitization procedure, children in the study are now able to eat a variety of foods containing milk protein, including yogurt, cheese, muffins, goldfish crackers, and even M&Ms. The research team intends to begin a new study to develop a method to combat peanut allergies.
Sources:
Science Daily
Food Allergy & Anaphylaxis Network
About.com: Food Allergy Basics
National Institute of Allergy and Infectious Dieseases