New Food Allergy Guidelines Out
Comprehensive Guidelines Aim to Help Doctors Diagnose, Treat Food Allergies
WebMD News Archive
Food Allergy Guidelines: Definitions and More
The guidelines define food allergy as "an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food."
It distinguishes allergies from intolerances. Foods that cause the same reproducible adverse reaction but don't have a likely or established immune system response are not considered allergies, but rather intolerances.
For instance, someone allergic to cow's milk due to an immune system response to milk protein has a food allergy. But someone who has a difficult time drinking milk due to an inability to digest the lactose in milk has a food intolerance.
Among the most common food allergies are reactions to:
- Tree nuts
Anaphylaxis, a serious allergic reaction that comes on rapidly and may cause death, can occur in response to food. Up to 65% of anaphylaxis cases are thought to be due to food.
Food Allergy Guidelines: Diagnosis
Under the new guidelines, the panel of experts recommends that intradermal or skin testing should not be used to make a diagnosis of food allergy.
The experts recommend skin puncture tests, in which a small amount of the extract of a suspected food in placed on the skin, then the skin is punctured through the droplet, to help identify possible troublesome foods but not to make a diagnosis based on it alone.
It also recommends against the routine use of measuring total blood IgE, the antibody formed in reaction to an allergen.
It recommends allergen-specific IgE blood testing but cautions that the test results alone are not enough to make a diagnosis.
Food elimination diets -- taking away one or a few specific foods to see if the reaction disappears -- may help.
Oral food challenges -- exposing the person to the suspected food under medical supervision -- are thought to be helpful.
If exposure to a certain food triggers symptoms, the doctor should then see if that finding matches with lab tests and medical history.
Food Allergy Guidelines: Management
Avoidance is best, the experts agree. They write: "There are nomedications currently recommended by the EP [expert panel] to prevent IgE-mediated food-induced allergic reactions from occurring in an individual with existing food allergies."
When food allergies trigger anaphylaxis, the experts recommend epinephrine injections first.