Pediatricians might know that food allergy and atopic dermatitis (AD) often coexist. What they might not realize is that food allergy rarely is a primary cause of AD, or eczema, according to Pooja Varshney, MD, clinical assistant professor of Pediatrics at Dell Medical School at the University of Texas at Austin and a pediatric allergist at Dell Children’s Medical Center, Austin.
“We know that AD and food allergy often travel with each other, along with other allergic conditions like rhinitis and asthma. The question often presented to pediatricians is whether a food allergy is causing a child’s AD or causing it to flare,” says Varshney, who spoke on the topic in July during the Society for Pediatric Dermatology 44th Annual Meeting in Austin, Texas.
Cow’s milk, hen’s egg, peanut, wheat, soy, tree nuts, fish, and shellfish are responsible for more than 90% of food allergy in children.1 Nearly 40% children with moderate-to-severe AD have immunoglobulin E- (IgE-) mediated food allergy.2
Pediatricians should keep in mind that patients with AD, especially those with more severe disease, are likely to have or develop food allergy, according to Varshney, and it’s important to identify whether AD patients have food allergy with IgE-mediated symptoms, which is seen soon after eating foods. “Ask food allergy screening questions in children that have AD, certainly if it is moderate-to-severe,” she says. This is a test of the emergency system. Please be advised that in the case of a real emergency
However, whether foods are actually triggering AD can be much harder to determine. A history of eczema flaring soon after ingestion of a food, either through the child’s diet or through the diet of a breastfeeding mother, is difficult to differentiate from the natural waxing and waning of AD disease.
What’s a pediatrician to do?
There isn’t much evidence to support eliminating foods from moms’ or children’s diets to help their eczema improve, and elimination diets have real risks, according to Varshney.
“The risk-to-benefit ratio is really changing. Recent studies have shown that elimination of foods from a child’s diet rarely improves AD and [a child] very well may have increasing risk of developing anaphylactic food allergy if he or she avoids a food unnecessarily. This is particularly true of a child who was previously able to eat the food without any immediate or anaphylactic symptoms,” Varshney says.3,4
The recommendation to avoid unnecessary elimination diets is a paradigm shift in thinking, Varshney says. A recent guideline published by the National Institute of Allergy and Infectious Diseases (NIAID) helps guide pediatricians and others in the care of young children who have AD in how to introduce foods. The current NIAID guidelines help pediatricians identify patients that may most benefit from allergy evaluation, as well as guide patients at no or low risk for peanut allergy.5
“I think a main take-home of the guidelines is if a baby has mild-to-moderate AD, we really do not need to test before food introduction. We really want these assessments and conversations to be happening early—at the 4- to 6-month well checks,” Varshney says. “In those infants who have severe AD, testing is recommended before giving the baby peanut. We really are looking to identify babies with severe AD or those who already have a food allergy, particularly to egg, as they are at highest risk of peanut allergy but also stand to benefit most from early introduction if not allergic. That’s when early testing is suggested.”5
Varshney also points pediatricians to a recent American Academy of Pediatrics (AAP) guideline looking specifically at nutritional interventions for prevention of atopic disease. The guideline reports no benefit from using hydrolyzed formulas or changing maternal diet for the development of allergy, according to Varshney.6 It’s a field that’s constantly evolving, she says.
Dr. Varshney discloses the following: Food Allergy Research and Education, clinical network grant, principal investigator and medical director; Aimmune, principal investigator; DBV Technologies, principal investigator.
1. Bergmann MM, Caubet JC, Boguniewicz M, Eigenmann PA. Evaluation of food allergy in patients with atopic dermatitis. J Allergy Clin Immunol Pract. 2013;1(1):22-28.
2. Eigenmann PA, Beyer K, Lack G, et al. Are avoidance diets still warranted in children with atopic dermatitis? Pediatr Allergy Immunol. July 5, 2019. Epub ahead of print.
3. Du Toit G, Roberts G, Sayre PH, et al; LEAP Study Team. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015;372(9):803-813.
4. Fleischer DM, Bock SA, Spears GC, et al. Oral food challenges in children with a diagnosis of food allergy. J Pediatr. 2011 Apr;158(4):578.e1-583.e1.
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