Guidelines for the Diagnosis and Management of Food Allergy in the United States: A Summary of the New NIAID-Sponsored Expert Panel Report

December 15, 2010

The new NIAID-sponsored Guidelines for the Diagnosis and Management of Food Allergy in the United States were released on December 6, 2010.  I thought it might be helpful if I provided a summary of the highlights of the report.  The full guidelines can be downloaded on the NIAID website at http://www.niaid.nih.gov/topics/foodallergy/clinical. 

The release of these guidelines has received significant media attention, although there is really very little, if any, new information included in them.  Much of the most recent information in the literature regarding such issues as component testing, extensively heated egg and extensively heated cow’s milk as well as decision trees based on IgE Immunocap blood testing or skin testing for performance of oral challenges in food-allergic children is only alluded to and unfortunately not really addressed in the guidelines. 

The following is a list of what I consider the most pertinent and clinically relevant statements and recommendations in the guidelines.  There is much more information in the full report.  I have included in parentheses additional information not included in the guidelines but that I think may be of interest.  This list is in no particular order of importance.

1. Atopic Dermatitis/Eczema:  Up to 37% of children under 5 years of age with moderate to severe atopic dermatitis have IgE mediated food allergy.  Food allergy testing should be considered in this group of children.  Infants who develop atopic dermatitis within the first 3 months of life are most often allergic to cow’s milk, egg and peanut.  Mutations of the skin barrier protein filaggrin, seen in a subset of patients with atopic dermatitis, may increase the risk for transcutaneous food allergen sensitization when infants come in contact with food allergens.  (There are reports in the literature that suggest this is especially true if the food is introduced to the immune system through the skin prior to exposure through the GI tract.  Initial GI tract exposure is more likely to induce tolerance.)

2. Severity of an Allergic Reaction: The severity of a future reaction to a food allergen cannot be accurately predicted by the severity of a past reaction, or by the level of specific IgE or the size of a skin prick test wheal.  One study showed that 44% of patients with documented peanut allergy who did not have an initial reaction that was life threatening, had subsequent reactions that were potentially life threatening.  (The higher the level of specific IgE and the larger the skin prick test wheal, the more likely it is that a patient will have clinical food allergy.  However, the severity of the allergic reaction associated with that allergy can not be predicted based on these test results.) 

3. Diagnosis of Food Allergy: The gold standard for the diagnosis of food allergy is a double blind placebo controlled food challenge, but single blind or open challenges may be considered.  (From a practical perspective, blinded placebo controlled food challenges are really only done in a research setting.  I perform open challenges in the office.)

4. Diagnosis of Food Allergy: Skin prick test results or food-specific IgE alone cannot be used to make a diagnosis of clinical food allergy.  They only indicate sensitization.  The test results must be considered within the context of a comprehensive history.  To diagnose a clinical food allergy, or rule it out, in a situation where there is a positive test result and no history of reaction to the food, an oral challenge must be performed.  (The problem of what to do with a positive result in a child who has never consumed the food allergen tested is a difficult one and underscores the need to do history-guided testing and to be cautious when ordering IgE Immunocap tests.  Unnecessary avoidance of foods to which a child is sensitized, but not clinically allergic, can lead to nutritional problems.)  

5. Gastrointestinal Issues Related to Food Allergy: Food allergy should be considered in infants and young children with eosinophilic esophagitis, enterocolitis, enteropathy and allergic proctocolitis.

6. Natural History of Food Allergy: The guidelines provide information on the natural history of food allergy in infants and children and at what age infants and children might outgrow a clinical allergy to foods such as cow’s milk, egg and soy.  The guidelines provide very little specific information on when to consider an oral food challenge in a child with a documented allergy to these foods.  (There is information in the literature referencing food-specific IgE levels and skin prick wheal sizes that address this.  My approach is to evaluate this information in conjunction with a comprehensive history and make a risk-benefit assessment on whether and when to do an oral challenge under supervision in my office, on a case by case basis.)

7. Cross Reactivity of Foods: The guidelines provide statistics on allergic cross reactivity of various foods such as the fact that at least 12% of individuals with tree nut allergy are clinically allergic to more than one tree nut.  It also states that 35% of infants with one food allergy develop an allergy to another food.  However, little specific guidance is given as to whether or not to do additional food allergy testing in infants and children with a documented allergy to a specific food.  (I approach this on a case by case basis and generally do some additional testing in children with a documented allergy to a specific food.  I generally confine additional testing to cow’s milk, soy, egg, wheat and peanuts as well as the foods that significantly cross react with the food to which the child is documented to be allergic.)

8. Breat Feeding: The guidelines recommend exclusive breast feeding for all infants for the first 4-6 months of life.  For infants at risk of developing food allergy (first degree relative with history of atopy including allergic rhinitis, asthma, atopic dermatitis or food allergy), the guidelines recommend hydrolyzed formula for the first 4-6 months if breast feeding is not possible.  Soy formula as an alternative is specifically not recommended.  (This is consistent with the American Academy of Pediatrics recommendations published in Pediatrics in January 2008: Pediatrics 2008;121;183-191)

9. Prevention: There is no evidence to recommend delaying introduction of any specific solid food, including those considered highly allergenic such as eggs, fish or peanut, beyond 4-6 months of age.  This applies to infants and children in general as well as infants at risk for food allergy.  There are no specific recommendations given for how to proceed in a child who already has one documented food allergy.  (This too is consistent with the American Academy of Pediatrics [AAP] recommendations published in Pediatrics in January 2008.   These recommendations are different from the AAP recommendations published in 2000 where a schedule of delayed introduction of foods was recommended.  The change in this recommendation is based on epidemiologic data indicating that there is no benefit in delaying the introduction of developmentally appropriate foods and even some data pointing toward an increased incidence of allergy when the introduction of food is delayed [see January 12, 2010 post on this blog as well as other food allergy posts on this blog]. )

10. MMR Vaccine: The MMR (measles, mumps and rubells) vaccine is safe for children with egg allergy, even for those with severe reactions.  (This is consistent with the most recent AAP recommendations.)

11. Influenza Vaccine: The guidelines state that there is insufficient evidence to recommend administering influenza vaccine routinely in patients with a history of hives, angioedema, allergic asthma or systemic anaphylaxis resulting from allergy to eggs.  The guidelines highlight that in one recent study 5% of patients with egg allergy and negative skin prick test results to influenza vaccine had systemic reactions to vaccination.  The guidelines discuss various approaches to giving influenza vaccine to children with egg allergy.  (I address this in my practice on a case by case basis doing a risk benefit analysis based upon the specific history and the results of IgE Immunocap and skin prick test results and an extensive discussion with the parents.  I have almost never had a patient who I have chosen to vaccinate after this type of comprehensive evaluation develop a systemic reaction to the influenza vaccine.)

12. Education: The guidelines state that people with food allergy and parents of children with food allergies need to be educated on how to properly read and evaluate a nutritional label.  The guidelines specifically recommend that people avoid foods with precautionary labeling such as “this product may contain trace amounts of allergen”. 

13. Treatment:  Epinephrine is the drug of choice for anaphylaxis and should be administered as first line therapy.  Fatalities from anaphylaxis are associated with delayed administration or improper use of epinephrine.  The use of antihistamines is the most common reason reported for not using epinephrine.  The highest risk groups for food allergy related anaphylaxis are adolescents and young adults, people with a prior history of anaphylaxis and patients with asthma.

Note: The content of this blog is for informational purposes only and is not meant as specific medical advice for a specific person.   If you have a medical problem, please contact your doctor.

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