How treating food allergies and AD has changed

Kristy Luciano is a Physician Assistant who graduated from Midwestern University-Downers Grove Physician Assistant Program in 1999.  She is an Assistant Professor and Director of Didactic Education at Midwestern University and serves as a Member at Large on the Board of Directors for the Society for Physician Assistants in Pediatrics.

Food allergies are a hot topic on the playground, at schools, and in pediatric offices. Parents of children with eczema or atopic dermatitis (AD) often have a lot of questions regarding the connection between eczema, exposure to common food allergens, and the development of or exacerbation of AD.  Pediatricians must advise families on when to start solid foods; if infants should be exposed to eggs, peanuts, or other common allergens; if labs should be ordered; and when they should be evaluated by a pediatric allergist.

The September 2019 issue of Contemporary Pediatrics addresses these issues in Food allergy: A trigger for atopic dermatitis? an article by Lisette Hilton. This article discusses many of the complex questions that clinicians must answer when evaluating pediatric patients with AD.

What comes first…

In the article, Dr. Pooja Varshney, clinical assistant professor of pediatrics at Dell Medical School at the University of Texas at Austin and a pediatric allergist states that food allergy is rarely the primary cause of AD. It is well known that food allergies, AD, and allergic rhinitis are related. This relationship is often explained by the term “atopic march”, indicating that some children start out with AD and subsequently develop allergic rhinitis and asthma. This article discussed another way to potentially think of this relationship. Rather than a direct march, these conditions may travel together, and are influenced by genetic and environmental factors.

Potential triggers

While food allergies may not cause AD, in some patients they may exacerbate the condition. The author, citing a recent guideline from the National Institute of Allergy and Infectious Disease, provides some helpful guidance for clinicians who evaluate children with AD. First, pediatricians should know that almost 40% of children with moderate-to-severe AD have immunoglobulin E- (IgE-) mediated food allergy. A thorough history in these patients should include questions regarding IgE-mediated allergy symptoms. If present, recommend strict avoidance, refer to an allergist, and consider prescribing an EpiPen.

Children with severe AD should be tested for an allergy before introducing peanuts. These patients should be evaluated by a board certified allergist trained in food allergy. Allergists can conduct skin prick testing, food challenges, provide advice on the safety of early introduction of peanut allergy in high-risk children who are not allergic, and provide follow-up to pediatric patients who have the potential to outgrow their allergies.

Order labs or refer?

Many pediatricians may be tempted to order food IgE panels in patients with AD. Parents may prefer this option as it is often simpler for families to address issues within the primary care setting rather than establish a new relationship with a specialist. However, ordering food IgE panels may cause more confusion than clarity as they can result in misdiagnosis. For instance, what do you say to the patient with AD who tests “positive” for egg allergy but eats eggs without allergy symptoms? The article reminds us that the diagnosis of allergy is most reliable when guided by a solid history and physical exam. In addition, the elimination of foods unnecessarily may increase the risk of developing an anaphylactic food allergy. This is especially important to remember in children with AD who are at higher risk for developing food allergies. When possible, evaluation by an allergist is in the patient’s best interest rather than eliminating a food he or she may not be allergic to.

Elimination diet

It can be difficult to make evidence-based management recommendations to families of infants with mild- to moderate-AD whose parents are concerned about food allergies. In the past, these parents may have been told to try an elimination diet, either in the mother’s or child’s diet depending on the age of the patient. Elimination diets were seen as a low-risk way to determine if eliminating common food allergens would improve the patient’s AD and perhaps help indicate a potential food allergen. The article in Contemporary Pediatrics reminds us that there is not much evidence to support management of AD with an elimination diet.  In fact, it may increase the patient’s risk of developing an anaphylactic food allergy.

The article also cites an American Academy of Pediatrics guideline regarding nutritional interventions for the prevention of AD. The guideline does not recommend changing the mother’s diet or support the use of hydrolyzed formulas to prevent the development of allergies.

Food allergies represent a constantly evolving field. This article helps clinicians stay up-to-date and navigate the daily decisions that will help protect their patients from food allergies and maximize control of AD.