Friday, 24 February 2017 05:29

Childhood Food Allergies

Written by  Dr. Laura M. Gober, Children’s Hospital of Philadelphia

Doctor taking a child's temperature.One in 13 children in the United States have a food allergy, a 50% increase overall and a 300% increase in peanut allergies during the 14 years from 1997 to 2011. This growing epidemic costs our health care system $24.8 billion each year. For families, food allergies affect everyday activities—meal planning, grocery shopping, attending social functions—in addition to creating significant financial burdens and stress.

The top eight food allergens are milk, egg, soy, wheat, peanut, tree nuts, fish and shellfish, accounting for 90% of all food allergies. And one-third of children have allergies to more than one food.

Some good news is that about 85% of allergies to milk, soy, egg and wheat will be outgrown by the time a child turns 3. But the bad news is that allergies to peanut, tree nuts, seeds and seafood are more likely to persist into adulthood. Luckily recent research is promising.

 

Diagnosing and Symptoms

Diagnosing a food allergy requires taking a complete medical history and doing a physical exam. It’s noteworthy that a child of a parent with an allergic disease (asthma, eczema, food allergies, hay fever) is more likely to have food allergies.

 Next, if a food allergy is suspected, it’s on to an allergist for testing. Some children may also need to see a nutritionist for possible nutritional deficiencies, such as lack of calcium with a milk allergy.

A specialist may recommend skin prick testing for suspected food allergies, plus blood tests. However, these tests alone are not definitive without a medical history, given the tests’ high false positive rates.

The most common symptom of a food allergy is a rash, such as hives. Gastrointestinal symptoms, such as vomiting or abdominal pain, and shortness of breath are also common symptoms.

More severe symptoms, such as anaphylaxis, may also occur. Anaphylaxis is a life-threatening allergic reaction that can send the body into shock. Unfortunately, 40% of people with food allergies experience it at some time.

A common myth is that prior symptoms and reactions predict the severity of future reactions. But since reactions can vary widely, children with food allergies and their parents must always be prepared for the possibility of anaphylaxis.

Factors contributing to the severity of reactions are—in addition to sensitivity to a particular food—the amount of allergen that’s ingested, any current illness (like a cold), a history of asthma, and exercise near the time of ingestion.

 

Treatments

While minor reactions, such as an isolated skin rash, can be treated with an antihistamine, severe reactions require the use of epinephrine—also known as adrenaline. Since delay in administering epinephrine increases the risk of a fatal reaction, those with food allergies must carry epinephrine auto-injectors at all times. In addition, all caregivers should be instructed on using these devices and have an Anaphylaxis Emergency Action Plan from a doctor.

And if food allergies weren’t stressful enough for families, the food allergy community was hit recently by huge price increases for epinephrine auto-injectors. The price of an EpiPen twin pack (manufactured by Mylan) rose to $600 in 2016 compared with its $100 price in 2009.

Although generic epinephrine auto-injectors are available (from Lineage and Mylan), they can still cost above $100 for two auto-injectors. Another option, Auvi-Q, is available once again, after its 2015 recall.

Imagine the cost to a family for a child who needs two twin-packs—one for home and one for school. Then add the cost each year, since injectors expire after about a year.

 

Managing Food Allergies Away From Home

The mainstay of treatment for food allergies has been strict avoidance of known food allergens. And a key step in avoiding those allergens is understanding the information on food labels.

A visit to an allergist can help educate parents on how to read food labels to keep their children safe. And although the top eight allergens are stated clearly and in common language on food labels, other allergens, such as sesame seeds, are not as easy to spot in prepared food.

The majority of accidental exposures to food allergens occur away from home—in places such as camps and schools, where each classroom has an average of two children with food allergies. As a result, schools have to be food allergy-savvy.

Some families develop a written plan for school that discusses necessary accommodations including what to do on field trips and how to manage food in the classroom.

Two important tips for kids with food allergies are never share food (because they don’t know for sure what’s in their friends’ food) and always wash hands before eating.

 

Laura M. Gober, M.D. - The Children's Hospital of PhiladelphiaThe Future of Food Allergies is Bright

In the U.S., clinical trials are seeking ways to desensitize those with food allergies. One of the most promising techniques, oral immunotherapy (OIT), involves gradually feeding someone their food allergen in increasing quantities until they’re desensitized or no longer react to the food.

With this technique, reactions to the food allergen can occur, so dosing needs to be supervised. It’s important to know that desensitizing a child to a food does not lead to tolerance—tolerance is long-lasting immunity without an allergic reaction to a food even if it’s not consumed daily. Those trying OIT must continue to eat the food every day to maintain their desensitization.

A variation of OIT currently in clinic trials is sublingual immunotherapy (SLIT), which involves giving patients small doses of an allergen under the tongue to boost tolerance and reduce symptoms.

Another approach, epicutaneous immunotherapy (EPIT), involves wearing a patch on the skin containing a food protein. A peanut patch shows promise for treating children and young adults with peanut allergy, with the Viaskin Peanut patch in phase III FDA trials. Clinical trials are also underway for a milk patch, with an egg patch on the horizon. See sidebar for most recent peanut allergy news.

Living with food allergies can be daunting and scary, but remember you’re not alone. Your local allergist can help with diagnosing and managing food allergies, and the American Academy of Allergy, Asthma and Immunology can help you locate a specialist.

Support groups and food allergy websites, such as the Food Allergy and Anaphylaxis Network and Kids with Food Allergies, can also be great resources, providing safety information, social support and updates on new developments.

 

Laura M. Gober, M.D., is an attending physician in the Division of Allergy and Clinical Immunology at The Children’s Hospital of Philadelphia. Dr. Gober also sees patients at the CHOP Care Network Brandywine Valley Specialty Care and Ambulatory Surgery Center. She completed a pediatric residency at the University of Maryland in Baltimore and finished her allergy fellowship at CHOP.