In the past, positive blood and skin tests would often be mistaken for a food allergy because they would indicate the presence of immunoglobulin E antibodies, but it is important to remember that these are typically higher in patients with atopic dermatitis, according to a speaker at the 69th Annual American Academy of Dermatology Meeting conducted in New Orleans this week. “Those antibodies are not diagnostic, and the only way to diagnose food allergy is with a strong history of reactions or a challenge,” Jon M. Hanifin, MD, of Oregon Health & Science University, said in a press release. “This is done in a doctor’s office, using small increments of the food in question and increasing the amount until an allergic reaction occurs or does not occur. Usually a parent can pinpoint if a child has a true food allergy because the allergic reaction will appear so quickly with lip swelling or hives, quite distinct from simply food intolerance.”
Between 6% and 10% of children have atopic dermatitis, and about one-third of these children have food allergy. Recent research examining the genetic basis of atopic dermatitis has shown that this chronic skin condition is likely related to a defect in the epidermal barrier, which allows irritants, microbes and allergens (such as food) to penetrate the skin and cause adverse reactions. Because the skin barrier in patients with atopic dermatitis is compromised and open to absorb proteins, it allows sensitization to certain foods, leading to a positive skin or blood test.
New guidelines recently issued by the National Institute of Allergy and Infectious Diseases established a protocol for the proper evaluation and management of food allergy. The guidelines recommend that children who are younger than aged 5 years with moderate to severe atopic dermatitis be considered for food allergy evaluation if they have persistent atopic dermatitis despite optimized management or if the child has a reliable history of an immediate reaction after eating a specific food.
Hanifin said research is also ongoing into whether withholding foods is leading to more allergies than an unrestricted diet in young children. This may provide future insight in potential ways to prevent food allergies. He said children in Israel seldom get peanut allergy, which may potentially be attributed to the use of peanut proteins in pacifiers in that country. In the United States and Europe, where peanut allergies are more common, infants are not usually exposed to this food until they are toddlers – the time when most peanut allergies are noticed.
“There is some thinking that withholding foods might actually be causing more allergies, and that an unrestricted diet may help tolerize babies to foods that could potentially cause a problem later in life,” Hanifin said. “Ongoing studies in this country using oral immunotherapy appear promising, and physicians hope that we may discover how to prevent food allergies in the future while continuing to provide successful treatment for children with atopic dermatitis.”
Source: Hanifin J. Food allergy and dermatology. Presented at: The American Academy of Dermatology 69th Annual Meeting; Feb. 4-8, 2011; New Orleans
A lack of testing for food allergies is putting children's health at risk and could lead to life threatening reactions, a study has found. The study, Adverse reactions to food in New Zealand children age 0-5 years, was published in the New Zealand Medical Journal. It looked at a cross-section of 110 children who had attended Plunket clinics. It found 44 had experienced an adverse reaction to food, but only four had been clinically evaluated. Those children were found to have adverse reactions to food allergens, including a life threatening peanut allergy. Two others had been hospitalised with systemic symptoms, but neither had undergone testing for food allergy. “If these children have food allergies, they remain at risk for continued and possibly severe reactions,” the study said.
Parents modifying children's diets or breastfeeding mothers cutting out food without advice from a physician or dietician could also have adverse affects, it said. “Failure to thrive is commonly seen in children experiencing FA (food allergy) as a result of multiple foods being removed from their diet.” The data indicated adverse reactions to food were a public health concern and may be under investigated — even when symptoms were severe, the study said.
“There is an urgent need to investigate the epidemiology, diagnosis, and prevention of FA (food allergy) in New Zealand to reduce morbidity, improve child health, and reduce the burden to health costs.” Thirty-three of the children were reported to have eczema. Ten had worsening symptoms two hours after eating, the study said. Symptoms improved in six of them with dietary changes. Doctors had prescribed topical therapy for 18 of those children with eczema, but symptoms had persisted.
“One possible explanation for this observation is undiagnosed FA (food allergy). Without testing, allergic triggers for eczema could not be identified in these participants.” Further investigation of food allergy as the cause of eczema was warranted, the study said.
Adverse reactions to food worldwide in children was an increasing concern and food allergy was as common in New Zealand as in other countries, the study said. The study was conducted by the Auckland District Health Board and led by Associate Professor Rohan Ameratunga and lead researcher Dr Christine Crooks. Allergy New Zealand chief executive Penny Jorgensen said the study was “really disturbing” because it highlighted that many children were not being assessed for food allergy. The risk was the potential for life-threatening reactions, she said.
A coordinating committee representing 34 professional organizations, advocacy groups and federal agencies oversaw the development of the guidelines. The coordinating committee selected a 25-member expert panel, chaired by Joshua Boyce, M.D., co-director of the Inflammation and Allergic Disease Research Section at Boston's Brigham and Women's Hospital. The panel used an independent, systematic literature review of food allergy and their own expert clinical opinions to prepare draft guidelines. Public comments were invited and considered as well during the development of the guidelines.
“These guidelines are an important starting point toward a goal of a more cogent, evidence-based approach to the diagnosis and management of food allergy,” says Dr. Boyce. “We believe that they provide healthcare professionals with a clear-cut definition of what constitutes a food allergy and a logical framework for the appropriate use of diagnostic testing and accurate interpretation of the results.”
Additional topics covered by the guidelines include the prevalence of food allergy, natural history of food allergy and closely associated diseases, and management of acute allergic reactions to food, including anaphylaxis, a severe whole-body reaction. They also identify gaps about what is known about food allergy.
“The food allergy guidelines provide a rigorous assessment of the state of the science, and clearly identify the areas where evidence is lacking and where research needs to be pursued,” says Daniel Rotrosen, M.D., director of the Division of Allergy, Immunology and Transplantation at NIAID. “This information will help shape our research agenda for the near future.”
Food allergy has become a serious health concern in the United States. Recent studies estimate that food allergy affects nearly 5 percent of children younger than 5 years old and 4 percent of teens and adults. Its prevalence appears to be on the rise. Not only can food allergy be associated with immediate and sometimes life-threatening consequences, it also can affect an individual's health, nutrition, development and quality of life. While several potential treatments appear promising, currently no treatments for food allergy exist and avoidance of the food is the only way to prevent complications of the disease.
More information on the guidelines may be found at http://www.niaid.nih.gov/topics/foodAllergy/clinical/Pages/default.aspx
Tips for Managing Food Allergy
Get a professional diagnosis. Don't try to diagnose a food allergy yourself. If you suspect that your child has a food allergy, discuss this with your doctor. He or she can advise you accordingly and may refer you to an allergist for additional testing and treatment if needed. You should work with your doctor and/or allergist to develop an action plan for managing the allergy through indicating which foods your child should avoid, and possibly prescribing medication, such as an antihistamine or, for severe reactions, self-injectable epinephrine (EpiPen® or Twinject®).
Pass around the plan. Give your child's food allergy action plan to people who regularly see your child, including relatives, caregivers and their friends' parents.
See an Accredited Practicing Dietitian. An APD like Nastaran can help you and your child identify foods and ingredients to avoid, and develop an eating plan to ensure your child gets all the nutrients needed to grow and develop properly. For example, if your child is allergic to milk, the dietitian will recommend other calcium-containing foods and beverages.
Always read food labels. Always read food labels to see if the product contains any of the eight major allergens, or other ingredients your child is allergic to. Since food and beverage companies continually make improvements, read the label every time you purchase a product. Teach your child how to read labels, too.
Get support at school. Meet with staff at your child's school to review and distribute your child's food allergy action plan. At minimum, involve your child's primary teacher, the school nurse (if there is one), and key food service staff. Make sure all supervisory staff your child sees during the school day and during after-school activities have a copy of the plan. It is highly recommended that school administrators, teachers, and even food service staff are aware of the food allergy action plan in the absence of a school nurse.
Be cafeteria cautious. Go over the school lunch menu with your child to identify foods to avoid. Work with food service staff to plan substitutions or pack a lunch for your child to take to school. Remind your child not to share or trade food with others and make sure they know which staff can help if they have questions about a food, or if they have a reaction to a food. Be sure your school food service staff has copies of the School Foodservice and Food Allergies information sheet and review it with them when you talk to them about your child's food allergies.
Ask questions when eating out. Most life-threatening allergic reactions to foods occur when eating away from the home. Explain your child's situation and needs clearly to your host or food server—and teach your child to do the same when you're not with them. If necessary, ask to speak with the chef or manager. Some fast food restaurants provide a list of the ingredients in their menu items, as well as information on whether any of the eight major allergens are present.
Keep an allergy-safe kitchen. Rather than singling out your food-allergic child, prepare allergy-free recipes the whole family will enjoy.
Make peers “allergy allies.” Encourage your child to talk openly with friends and classmates about their allergy, what foods they must avoid, and what could happen to them if they don't. Suggest that your child enlist their friends in helping them “stay on the alert” for foods in question so they won't get sick.
Most importantly, be ready for emergencies. Teach your child the possible symptoms of a serious allergic reaction (anaphylaxis), such as difficulty breathing or swallowing, or tingling in the hands, feet, lips or scalp. If they experience symptoms after eating a food, make sure they know to immediately call 0-0-0 and, if prescribed by your allergist, use their medication to treat the reaction. If possible, have your child wear a medical alert bracelet or necklace that identifies the specific allergy. Every few months, “role play” an allergic reaction to make sure your child knows what to do.
For more information and resources on managing food allergies see Nastaran or your doctor.
Source: International Food Information Council