Why are Childhood Allergies so Common?

These days you're more than likely acquainted with a child who has allergies. According to the U.S. Center for Disease Control and Prevention (CDC), an estimated 3 million children under 18 had a food allergy in 2007—an 18 percent increase since 1997.

And food isn't all they're allergic to.

Hay fever, eczema, and asthma are also prevalent in children. Currently, 6.2 million American kids suffer from asthma-a condition often triggered by allergies to seasonal pollens and other environmental toxins such as dust and mold.

Why are Allergies so Common?

"There are several factors contributing to the overall rise in allergies but in the last five years there appears to be some leveling off," says Tracy Fausnight, MD, a pediatric allergy and immunology specialist at Penn State Children's Hospital in Hershey, PA. "Living more hygienically. The increased use of day care. Eating out more and consuming more processed foods. Even the increased use of acetaminophen--all could be playing a role in our current predicament."

Acetaminophen may reduce the level of antioxidants in the body and prolong the illness from rhinovirus infections which are also a common cause of childhood asthma.

The immune system is also being weakened by cleanliness, antiobiotics, and vaccines. "The hygiene hypothesis holds that if the immune system isn't required to work fighting off infections-it gets lazy which opens the door for allergic reactions," says the immunologist and mother of three."

On the food allergy front, there's a difference between food sensitivity and an actual allergy, Fausnight explains. Hives, wheezing, swelling, skin rashes, and vomiting are typical immune responses to food. "Changes in behavior are not caused by food allergies."

New Treatment Options for Food Allergies Hold Promise

Anti-inflammatory agents such as corticosteroids which are usually inhaled and bronchodilators, medicines that expand the bronchial air tubes, are the two types of medicines used to treat asthma.

While inhaled corticosteroids therapy continues to be the preferred treatment for persistent asthma, there is a different class of anti-inflammatory medications known as leukotriene inhibitors which block the activity of chemicals called leukotrienes (LOU-koh-treenz) that are involved in airway inflammation.

None of these treatment options change the immune system, however. If you want to end the allergic reaction, Fausnight recommends regular allergy shots. "Though not terribly convenient, regular shots are the only therapy that has the potential to cure the problem."

However, the future of anti-IgE looks hopeful. An anti IgE antibody that is used for treatment of allergic asthma has been studied for food allergies but was unsuccessful. "In the past there were attempts to treat food allergy with allergy shots just like other allergies but there were deaths when it was attempted," explains Fausnight. "Oral immunotherapy seems to be a better option for food issues."

There have also been clinical trials of the Chinese herbal formula FAHF-2. In experiments with mice, scientists found that peanut allergy was significantly reduced using this remedy. Immunotherapy may be the future. In this treatment, tolerance is increased by giving patients increasing amounts of an allergen (like milk) over time. "There may well be an effective oral food allergy treatment in the near future," Fausnight says.


Interview with Tracy B. Fausnight MD
Assistant Professor of Pediatrics, Section Chief, Allergy and Immunology
Division of Rheumatology, Allergy, and Immunology
Penn State Children's Hospital

Centers for Disease Control and Prevention

American Academy of Pediatrics

Kids with Food Allergies.org

American Thoracic Society