Oral Allergy Immunotherapy Helps Control Asthma

TUESDAY March 4, 2008 -- Oral allergy immunotherapy -- in the form of drops or tablets -- is effective at reducing asthma symptoms and the need for asthma medications in children who have what's known as allergic asthma, a new study finds.

The findings bolster hopes that these oral medications might someday replace injections, never a hit with kids.

"[Oral] immunotherapy is effective and safe, easy to administer, well-accepted by patients," said the study's senior author, Dr. Giorgio Walter Canonica, professor of allergy and respiratory disease at the Medical University of Genoa, Italy.

Commonly known as allergy shots in the United States, allergy immunotherapy works in a manner similar to vaccines -- essentially re-educating the body's immune system so that it doesn't overreact to harmless substances such as pollen or dust mites. While this therapy can be effective, it's currently only available via injections in the United States, and usually involves at least one to two shots a week for three to six months, making it a less-than-popular alternative with children.

Oral immunotherapy is available in Europe, but has yet to gain Food and Drug Administration approval in the United States.

The new study reviewed nine studies that looked at the use of so-called sublingual (oral) immunotherapy in children with asthma. A total of 441 kids between the ages of 3 and 18 who had been diagnosed with allergic asthma were included in the studies. Allergic asthma means that asthma symptoms can be triggered by exposure to an allergen, such as dust mites, pollen or mold.

Two hundred and thirty-two children received oral immunotherapy and the remaining 209 got a placebo.

The dosing schedule varied depending on the study and whether drops or tablets were used. Canonica said that during the maintenance phase of immunotherapy, drops or tablets were given three times a week. The average duration of the studies was 12 months. The most common allergen treated was dust mites. Grass mix and pollen were also included in one study each.

The researchers found that those taking sublingual immunotherapy (SLIT) had significantly fewer symptoms and needed to take less asthma medication. Not enough of the studies included measurements of lung function for the new study to assess whether SLIT affects lung function significantly.

"SLIT is highly effective in treating pediatric asthma patients, reducing both symptoms and medication use," said Canonica, who's also president of the World Allergy Organization.

Additionally, SLIT appeared to be better tolerated than allergy shots. The chances of a severe reaction are less with oral immunotherapy than with the injected type, according to Dr. Andrew MacGinnitie, an allergist/immunologist at Children's Hospital of Pittsburgh.

"There have been some rare cases of severe reactions with SLIT, but they're much less common," MacGinnitie said. Another big benefit, he added, is that "shots have to be given in the doctor's office and drops are designed to taken at home."

The results of the new study are published in the March issue of the journal Chest.

Other studies have directly compared SLIT to allergy shots and they're both equally effective, according to Canonica. And MacGinnitie said that, "immunotherapy is really the only treatment that gets to the cause of the allergic response."

"This is a potentially new and exciting treatment for kids with asthma," he concluded.

More information

To learn more about allergy immunotherapy, visit the American Academy of Allergy, Asthma and Immunology.

Posted: March 2008


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