Newswise — The prevalence of food allergies is rising, and although strict avoidance is currently the only treatment, new effective therapies are currently being developed according to experts at the annual meeting of the American College of Allergy, Asthma and Immunology (ACAAI) in Seattle.
"Interval comparison studies on the same population, using the same methodology indicate food allergy " especially peanut allergy " has increased significantly," said Sami Bahna, M.D. DrPH, professor of pediatrics & medicine, chief of Allergy & Immunology, Louisiana State University health Sciences Center, Shreveport, La.
In the United States, food allergies are now estimated at 3.7 percent in adults and 6 percent in children, he said. Random phone interviews in 2002 showed peanut and tree nut allergy in the general population to be 1.2 percent. Compared to a similar survey in 1997 the prevalence doubled.
"Allergies and asthma are increasing, and the main manifestations of food allergy are increasing, including atopic dermatitis, anaphylaxis, and eosinophilic gastrointestinal disorders," Dr. Bahna said.
He attributes the increasing causes of food allergy to the increase in:"¢ Food consumption and obesity, including the highly allergenic foods: fish, peanut, tree nuts, milk, egg and soy."¢ Eating out, and the prevalence of buffet restaurants and "all you can eat." "¢ Food varieties and food cross-reactivities."¢ Food cross-reactivities with non-ingestant allergens, such as latex, cockroach, dust mite and pollen."¢ Commercial foods incorporating multiple nutrient and non-nutrient allergenic ingredients."¢ Incorporation of food proteins in medical diagnostic and therapeutic agents, particularly dermatologic.
According to Dr. Bahna, factors that seem to contribute to the increase in food allergy include: high survivorship of atopic subjects allowing the spread of the genetic traits; the hygiene hypothesis; caesarean section deliveries; use of antacids; and use of infant multivitamins.
Reactions to food allergy can be severe and even fatal. Current treatments are strict avoidance of the offending food, which is very difficult to accomplish, and treating reactions as they occur.
Robert A. Wood, M.D., professor of pediatrics and international health, and director, Pediatric Allergy and Immunology at Johns Hopkins University School of Medicine in Baltimore, Md., said there are currently three approaches to the treatment of food allergy in development: anti-IgE antibodies, Chinese herbal remedy and immunotherapy.
"Anti-IgE therapy at the highest dose would protect most patients (75 percent) from reactions due to accidental exposures, but it is a medicine, not a vaccine, and it must be given on a continuous basis," said Dr. Wood. "Although it could be used for any food allergy, it doesn't work if patients are too allergic, and there are concerns about its safety and cost."
The first clinical trial for food allergy was recently initiated with Chinese herbal formula FAHF-2. Studies in mice showed allergic reactions on a variety of measures of peanut allergy were markedly reduced and no side effects were seen.
"Immunotherapy induces tolerance to an allergen by giving gradually increasing doses of the allergen. In food allergy, the risks of traditional immunotherapy (subcutaneous injections of intact allergen) have far outweighed the benefits, but new approaches may change this equation," he said.
Several preliminary studies on oral or sublingual immunotherapy for food allergy have very encouraging results, with strong evidence of at least short term desensitization.
Preliminary research finding also show modified allergens, including peptide vaccines and mutated recombinant vaccines, offer promising new treatments.
The Food Allergy Research Consortium, sponsored by the National Institutes of Health, is dedicated to the study of food allergy with five years of initial funding. Three studies are underway: an observational study of infants with eczema and food allergy; oral egg immunotherapy; and sublingual peanut immunotherapy study. A fourth study on recombinant peanut vaccine safety study is currently in development.
"Progress will be slow, but truly effective treatment for severe, persistent food allergy will be developed in the next 10-20 years," said Dr. Wood.
Food allergy is the single leading cause of anaphylaxis. Anaphylaxis is the most severe form of allergic reactions, affecting multiple organ systems. Symptoms can include chest tightness, wheezing, nausea, vomiting, cramping, hives and swelling of the lips and joints. The most dangerous symptoms are breathing difficulties, throat swelling, chest wheezing, dizziness, low blood pressure, shock and loss of consciousness, all of which can be fatal. Patients with severe reactions should have continued access to self-administered epinephrine injections.
Patient information on allergic diseases including food allergy is available by calling the ACAAI toll free number at (800) 842-7777 or visiting its Web site at www.acaai.org. For food allergy patient information or support, call the Food Allergy and Anaphylaxis Network (FAAN) at (800) 929-4040 or visit online at www.foodallergy.org.
About ACAAI
The American College of Allergy, Asthma and Immunology (ACAAI) is a professional medical organization headquartered in Arlington Heights, Ill., that promotes excellence in the practice of the subspecialty of allergy and immunology. The College, comprising more than 5,000 allergists-immunologists and related health care professionals, fosters a culture of collaboration and congeniality in which its members work together and with others toward the common goals of patient care, education, advocacy and research.
Annual Meeting Online Press Room:www.acaai.org/public
Annual Meeting Final Program:www.acaai.org/member
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