Physicians have watched food allergies in children trending upward over the past decade, with an 18 percent increase between 1997 and 2007. Today, about 3 million children younger than 18 have a food or digestive allergy.
The reasons why food allergies are on the rise aren’t specifically known, but Thomas M. Leath, MD, a Scott & White pediatric allergist in Round Rock notes it could be a combination of both physicians and parents being more aware, the types of diets children consume and something called the “hygiene hypothesis.”
“The hygiene hypothesis is based on the assumption we live in a society that is too clean,” Dr. Leath explained. “Our immune systems become bored and use their abilities to trigger inflammatory disease in our systems instead of fighting infection.”
The United States’ western diet—high in saturated fats and processed sugars—is also thought to play a role in making children more susceptible to developing allergies. In developing countries, children’s diets are more vegetarian and comprised of home grown foods, producing a natural and rich variety of gut bacteria used to break down food and stave off infection. Western diets, along with better sanitation methods and immunizations, drastically decrease that biodiversity in gut bacteria. This results in a smaller number and variety of “good” microbes, disrupting normal digestive function.
Another potential cause in the rise in pediatric food allergies is the delay in exposing children to possible allergens. “We typically recommend that parents of children at risk for food allergy wait through the first several years of life to expose their children to foods that may trigger a reaction,” explained Dr. Leath, noting sometimes the reasoning is due to existing allergies in one or both of the parents. “The research on the effectiveness of this has been mixed,” he continued, “and some recent research suggests that the delay may increase the risk in some children.”
The Common Culprits
The most common foods children are allergic to include peanuts, tree nuts (almonds, cashews, pecans, walnuts), milk, eggs, soy, shellfish and wheat. Dr. Leath notes that about 80 percent of children will outgrow their allergies to milk, eggs, soy and wheat by the time they enter Kindergarten. Only about 20 percent, however, will fully outgrow their allergies to nuts or seafood.
Is it Intolerance or Allergy?
Distinguishing between a food intolerance and a food allergy is the first step in diagnosis and treatment, Dr. Leath explains. A food intolerance will make someone uncomfortable, says Dr. Leath, like an intolerance to lactose. “A child might become bloated or experience abdominal discomfort, but it isn’t life threatening.”
Allergies, on the other hand, are caused by the body’s immune system, and can trigger any of these symptoms:
- Swelling of the lips/tongue/throat; tingling in the mouth or throat
- Asthma-like symptoms, including coughing/wheezing
- Intestinal tract reactions including nausea/diarrhea/cramping
- Changes in the cardiovascular system (dropping of blood pressure)
- Anaphylactic shock
Because the severity of an allergic reaction is so unpredictable, Dr. Leath stresses the importance of being prepared and educated. “Parents and children alike need to know the warning signs and understand how to get treatment quickly.
“When there is a confirmed allergen, avoidance is the best medicine,” he added. “There are also a number of organizations and resources that provide practical information on how to substitute ingredients in recipes, like how to make a birthday cake for your one-year-old who is allergic to eggs.”
And emergency preparedness is the name of the game when the allergen causes a severe reaction. “The child should wear a medic alert bracelet, and if old enough, carry and know how to use an epinephrine pen,” Dr. Leath said.
Current research includes oral immunotherapy, which involves the oral administration of food allergens in the hope the body will build a tolerance or possibly cure itself of the allergy. “We don’t know yet if either is really achievable, or maybe this kind of treatment will at least provide a safety net for those who are highly allergic in the event of an accidental exposure,” Dr. Leath said. “More testing needs to be done.”