The Rapid Rise of Food Allergies in Children

Nov. 12, 2008 — Rates of food allergies in children, such as milk, peanuts, and fish, are rising rapidly in the US.

An estimated 3 million children, younger than the age of 18, had a food allergy in 2007, an 18 percent increase since 1997, according to the US Centers for Disease Control and Prevention (CDC).

Researchers reported earlier this week on new therapies and approaches to treat food allergies, at the American College of Allergy, Asthma and Immunology's (ACAAI) annual meeting, in Seattle. "The problem is even more than numbers," says Dr. Sami L. Bahna, a professor of pediatrics and medicine and chief of allergy and immunology at Louisiana State University Health Sciences Center. "The severity of food allergies is going up."

According to Dr. Bahna, there has been an increase in severe rashes; severe attacks of airway obstruction, called anaphylaxis; and intestinal problems. "What's more, the method of exposure that results in an allergic reaction is also changing." says Dr. Bahna. "People used to react by eating the food, but there are many people now that react by touching or smelling the food."

Contributing Factors
Food allergies are not the only allergies on the rise, says Dr. Bahna. "All the allergies are increasing - asthma, hay fever, eczema."

Last month, the National Center for Health Statistics (NCHS) reported that four children out of every 100 will be diagnosed with food allergies. Children with food allergy are two to four times more likely to have other related conditions such as asthma and other allergies, compared with children without food allergies. According to the report, from 2004 to 2006, there were approximately 9,500 hospital discharges per year with a diagnosis related to food allergy among children younger than the age of 18.

Experts say that several factors are contributing to the increase in allergies. The first is the so-called "hygiene hypothesis," which states that people in industrialized countries are living in increasingly sterile environments. As a result, their immune systems do not have to fight as many infections, which can lead to a hyperactive system.

"When there is some degree of unhygienic conditions, the immune system from infancy adapts and develops to fight infection," Dr. Bahna says. "Cleanliness, antibiotics, whether they are needed or not, and vaccinations are allowing the immune system to develop as if - I don't need you." Other factors leading to the rapid rise of allergies are the increased use of antacids among children, which prevents stomach acid from doing its job, and the increased use of multivitamins.

Dr. Bahna says eating more highly allergenic foods such as fish, peanuts, tree nuts, milk, eggs, and soy, as well as the increasing rates of childhood obesity, contributes to development of food allergies.

According to Dr. Bahna, eating out hikes the risk for food allergies because you do not have total control over what you are eating. Ingredients in processed foods can also trigger allergic reactions.

The Severity of Allergic Reactions
According to the NCHS, food allergy is a potentially serious immune response to eating specific foods or food additives. Eight types of food - milk, eggs, peanuts, tree nuts, fish, shellfish, soy, wheat - account for over 90 percent of allergic reactions in people with food allergies. Mechanisms describing how a person develops an allergy to specific foods are largely unknown.

Depending on the severity of the allergy, reactions to foods can range from a tingling sensation around the mouth and lips and hives to life threatening conditions. Food allergy is more common in children than adults, and a majority of affected children will outgrow food allergies with age. However, food allergy can sometimes become a lifelong concern.

New Treatments for Food Allergies
The current treatment instructs individuals to avoid problematic foods and treat the symptoms of the reaction. Dr. Bahna says that new treatments may be on the way.

Also, at the annual ACAAI meeting, Dr. Robert A. Wood, director of pediatric allergy and immunology at Johns Hopkins University School of Medicine, discussed the use of anti-IgE antibodies, a Chinese herbal remedy and immunotherapy, as a potential new treatments for food allergies. Anti-IgE therapy disrupts the sequence of events that causes an allergic reaction, says Dr. Wood.

The treatment appears to be effective in almost 75 percent of patients. Drawbacks include the treatment will not work in patients who are too allergic, and it must be given continuously. There are also concerns about the safety and cost of the treatment, says Dr. Wood.

According to Dr. Wood, the first clinical trial of the Chinese herbal formula FAHF-2 is underway. In experiments with mice, scientists found that peanut allergy was greatly reduced using this treatment.

Currently, Dr. Wood is involved in developing the most promising approach to treating allergies, immunotherapy. In this treatment, tolerance is increased by administering increasing amounts of an allergen to patients over a period of time.

"This is sort of like the allergy-shot model," says Dr. Woods. "We are cautiously optimistic that we are on the right path."

Always consult your physician for more information