MILWAUKEE (AAAAI) -- Immunotherapy, or "allergy shots," may help prevent the development of asthma in children with seasonal allergies, according to a study by European researchers in the February issue of the Journal of Allergy and Clinical Immunology (JACI). The JACI is the peer-reviewed, scientific journal of the American Academy of Allergy, Asthma and Immunology (AAAAI).

There is a clear link between allergies and asthma. Allergic rhinitis (also called hay fever or seasonal allergies) frequently precedes the development of asthma. More than 70% of asthma patients report having nasal symptoms, and about 20% of patients with allergic rhinitis develop asthma. Up to 50% of seasonal allergy sufferers experience bronchial hyperresponsiveness (irritated airways) during pollen season.

In this study, 205 children, each with a history of allergy to birch and/or grass pollen, were randomly assigned to one of two groups, the immunotherapy group or the control group. All children were given an initial evaluation to determine the severity of their allergies and whether or not they had asthma. After this evaluation, the immunotherapy group began treatment-weekly injections for the pollen they were allergic to, followed by maintenance doses every six weeks for a total of three years. The control group received no treatment. All children were allowed to take medications to alleviate allergy and asthma symptoms.

Among the 151 children who did not have asthma before treatment, fewer children in the immunotherapy group developed asthma than in the control group.

Immunotherapy Group
No asthma following treatment--60
Had asthma following treatment--19
Percent that developed asthma--24.1%

Control Group
No asthma following treatment--40
Had asthma following treatment--32
Percent that developed asthma--44.4%

After three years of treatment, broncial hyperresponsiveness scores improved in both groups, but the improvement was more significant in the immunotherapy group.

During Pollen Season
Immunotherapy Group
Bronchial Hyperresponsiveness Score Before Study--10.4
Bronchial Hyperresponsiveness Score at the End of Study--14.9

Control Group
Bronchial Hyperresponsiveness Score Before Study--11.1
Bronchial Hyperresponsiveness Score at the End of Study--12.2

During Winter
Immunotherapy Group
Bronchial Hyperresponsiveness Score Before Study--12.8
Bronchial Hyperresponsiveness Score at the End of Study--17.2

Control Group
Bronchial Hyperresponsiveness Score Before Study--13.5
Bronchial Hyperresponsiveness Score at the End of Study--14.3

Immunotherapy is successful in up to 90% of patients with seasonal allergies. The immunotherapy affects the natural course of allergies by altering a person's response to allergens on an immunologic level. Researchers theorized that if immunotherapy is able to improve symptoms in one portion of the airways (i.e., nose), it also could give the same immunologic protection to another part (i.e., the lungs), and that it could change the natural course of allergic disease by preventing the immunologic response to allergens.