Immunotherapy may benefit allergic preschoolers

By Megan Rauscher

NEW YORK (Reuters Health) - Although there is controversy over the use of immunotherapy among children younger than 6 years old, a new study shows that it is safe and effective for the treatment of hayfever in this age group and may prevent the later development of more allergies and asthma.

In a review of the medical records of one Midwest allergy clinic from 1992 to 1997, Dr. Zachary D. Jacobs from the University of Missouri in Columbia and colleagues identified 59 patients between 18 months and 5 years of age treated with standard immunotherapy for hayfever.

The procedure, also called "allergen-specific subcutaneous immunotherapy," involves injections under the skin of extracts of the substance that causes the allergic response (the allergen). This results in the suppression of the allergic response during subsequent exposure to the allergy-causing substance. However, the treatment can cause adverse effects, including anaphylaxis, a severe, potentially life-threatening allergic reaction.

All of the children had symptoms consistent with hayfever (also referred to as allergic rhinitis), did not completely respond to previous therapy, and had at least one positive result on a skin prick test.

According to the investigators, new sensitivities decreased by 10 percent in children as young as 18 months who received subcutaneous immunotherapy. In contrast, new sensitivities increased by 62 percent, a statistically significant percentage, compared with a group of age-matched asthmatic children who did not receive immunotherapy.

The findings were presented over the weekend at the annual meeting of the American College of Allergy, Asthma and Immunology in Seattle.

Commenting on the findings, Dr. John Oppenheimer, director of clinical research at the Pulmonary and Allergy Association in New Jersey, who was not involved in the study, said: "We know that asthma and allergies are both rising in prevalence, so what this abstract reinforces to me is that maybe we should be considering introducing these disease-modifying therapies earlier on -- that is, in younger children."

On the other hand, Dr. Gailen D. Marshall of the University of Mississippi, Jackson, and Editor-in-Chief of the Annals of Allergy, Asthma and Immunology said: "I would argue very strongly that more study needs to be done before I'm ready to put my 18-month-old grandchild on immunotherapy...There has to be a proven benefit-to-risk ratio for this treatment. In terms of sensitization, these data certainly support that."