NEW ORLEANS – Food allergy continues to be misdiagnosed, in part because of clinician reliance on patch tests and food avoidance tests rather than on overt clinical signs of food allergy, according to Dr. Jon Hanifin of Oregon Health and Science University in Portland.
Photo credit: © Julián Rovagnati/Fotolia.com
Peanuts, milk and eggs are among the most popular food allergens.
Also, clinicians are often responsive to parents’ insistence that their children have food allergies. About 75% of what parents suspect to be food allergies are really just food intolerance, Dr. Hanifin said at the annual meeting of the American Academy of Dermatology.
Food allergies typically have a rapid-onset reaction, usually consisting of urticaria, swelling, and respiratory or gastrointestinal symptoms, he said. The most common food allergens are egg, milk, peanut, soy, wheat, and fish
In 2010, the National Institute of Allergy and Infectious Diseases issued new guidelines for the diagnosis and treatment of food allergies. The result of evaluations by a 25-member expert panel, which included three dermatologists, the guidelines were based on a systematic review of the available evidence from the Rand Corp. (JAMA 2010;303:1848-56).
The report concluded that food allergies affect at least 1%-2% – but fewer than 10% – of the United States population, and that most testing is not sufficient to diagnose the condition. Furthermore, food allergy has been misdiagnosed as a result of inadequate diagnostic criteria and the limited sensitivity and specificity of IgE testing.
In the guidelines, food allergy is now defined as an adverse health effect arising from a specific immune response that occurs upon exposure to a given food, said Dr. Hanifin.
Despite the publication of those guidelines, the nature of food allergies continues to be misunderstood, and clinicians continue to struggle to diagnose food allergies, he said. The costs of these misunderstandings include unnecessary visits to physicians and alternative practitioners, expensive test panels, and the expense of special foods. Some children even end up with impaired nutrition or poor growth as a result of dietary changes that were made in the belief that they would alleviate the allergy.
Dr. Hanifin reported no conflicts relevant to this talk.