The Year in Allergy:
Advances in allergic disease research strong in 2004

MILWAUKEE – Several advances in the diagnosis and treatment of allergic disease were published throughout 2004 in the Journal of Allergy & Clinical Immunology (JACI). The JACI is the peer-reviewed scientific journal of the American Academy of Allergy, Asthma & Immunology (AAAAI). Allergies and asthma have a major impact in the United States, affecting over 50 million Americans and accounting for approximately 20 billion in healthcare costs each year.

“The rising prevalence and health care costs of allergic disease has created a need for new research.” said Donald Y.M. Leung, MD, PhD, FAAAAI and Editor of the JACI. “The many interesting articles published this year in the Journal of Allergy and Clinical Immunology indicates heightened interest in this field and highlights the great strides that are being made in the diagnosis and treatment of this common group of illnesses.”

The following are summaries of three important studies that were featured in the JACI in 2004.

Early infection proves beneficial later in life
Children who have a fever before age one are less likely to develop allergies at age 6-7 years, according to a study featured in the February JACI. The study noted that fever was common in the first year of life, affecting 46.9% of the children evaluated.

After evaluation at age 6 to 7 years, researchers discovered that allergic sensitization and atopic asthma were significantly less common among children who had fevers in their first year. Researchers also found that each time a child had a fever, the odds of them developing allergies later in life were reduced.

These findings provide direct support for the hygiene hypothesis, which suggests that exposure to infections early in life decreases the risk of developing allergies. More information is need about the types of infections that protect against allergies and the pathways by which they mediate their effect.

Man's best friend offers protection against allergies
Exposure to dogs in the first year of life enhances the development of the immune system, which reduces allergic sensitization and atopic dermatitis. These findings were featured in a study in the February JACI by researchers from the University of Wisconsin-Madison.

Researchers found that home exposure to dogs, but not cats, in the first year of life was associated with a reduction in atopic dermatitis, an itchy skin rash common in allergic families. They also discovered that dog exposure enhances the production of interleukin-10, an immune system hormone with potent anti-inflammatory properties.

The findings raise the possibility that enhanced production of the hormone IL-10 is responsible for a lower risk of developing allergies. Greater understanding of mechanisms that modify immune development to promote tolerance in infancy may lead to new preventative strategies for allergic diseases.

Breastfeeding decreases asthma development
A study in the October 2004 JACI reported that breastfeeding reduces the risk of asthma in children in the first four years of life. Researchers evaluated the relationship between breastfeeding and asthma in more than 4,000 newborns and discovered that four year olds who had been exclusively breast-fed for the first four months showed a lower risk of asthma.

The researchers had previously shown the same results in children at 2 years of age. However, this study expanded on those findings, showing that a more prolonged period of breastfeeding not only reduced the risk of asthma during the first four years of life, but it also appeared to reduce the severity of the disease as well.

December AAAAI Topic of the Month – www.aaaai.org
These studies and more are featured in the December AAAAI Topic of Month, featured on the AAAAI Web site, www.aaaai.org. The Topic of Month, entitled Year-in-Review: Advances in Allergic Disease highlights research published in the JACI that has made an impact in the treatment and management of allergic disease in 2004. The Topic of the Month feature can be accessed by clicking on the feature box on the AAAAI homepage, www.aaaai.org.

To find an allergist/immunologist in your area or to learn more about allergies and asthma, call the AAAAI Physician Referral and Information Line at 1 (800) 822-2762 or visit the AAAAI Web site at www.aaaai.org.

The AAAAI is the largest professional medical specialty organization in the United States representing allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Allergy/immunology specialists are pediatric or internal medicine physicians who have elected an additional two years of training to become specialized in the treatment of asthma, allergy and immunologic disease. Established in 1943, the AAAAI has more than 6,000 members in the United States, Canada and 60 other countries. The AAAAI serves as an advocate to the public by providing educational information through its Web site at www.aaaai.org.

# # #

EDITOR'S NOTE: These studies were published in the peer-reviewed, scientific journal of the American Academy of Allergy, Asthma and Immunology, but do not necessarily reflect the policies or the opinions of the AAAAI. To receive a copies of the above studies, please contact John Gardner (jgardner@aaaai.org) at (414) 272-6071.