Hope Springs Eternal: New Help for Seasonal Allergies
By Colette Bouchez, HealthScoutNews Reporter
FRIDAY, May 2 (HealthScoutNews) -- While most people are happy to bid farewell to the cold and snow of winter, not everyone is equally excited to see spring and summer arrive.
The reason: Seasonal allergies, a problem that plagues some 35 million Americans beginning as early as March and often lasting clear through the first frost.
"Spring and summer allergies are extremely common, mostly because there are so many different allergens that come into bloom this time of the year," says Dr. Clifford Bassett, an allergy and asthma specialist at New York University Medical Center.
Whether it be trees, grass, flowers or weeds, when the small, dry, light pollen becomes airborne, simply taking a deep breath outdoors can leave you sneezing, wheezing, tearing and itching for up to six months of the year.
To heighten awareness of the problem and educate people about treatments new and old, May is designated Asthma and Allergy Awareness Month.
While some relief from allergies can be found through practical means -- such as keeping windows closed and staying indoors when pollen counts are high -- for many people spring and summer survival is made possible by any number of medications designed to stifle allergic reactions. These include antihistamines, nasal decongestants and anti-inflammatory nasal sprays -- many of those now available over-the-counter, as well as by prescription.
However, a brand new class of prescription drugs is posed to join the anti-allergy arsenal. Known as Anti-IgE, it just may revolutionize not only the way seasonal allergies are treated, but also the treatment of asthma as well as food and drug sensitivities.
"It is the first phase of a new kind of treatment for allergy disease -- and it holds some very exciting promise," says Dr. Lanny Rosenwasser, president of the American Academy of Allergy, Asthma and Immunology and a researcher and allergist at the National Jewish Medical and Research Center in Denver.
Regardless of what you are allergic to, the cascade of biochemical events that make up an allergic reaction are remarkably similar. Key to the process is an immune system antibody known as IgE -- or immunoglobulin E.
With a seasonal allergy, airborne pathogens -- particularly pollen -- are inhaled, and as they enter the body they bind to the IgE antibodies. These antibodies, in turn, bind to nearby mast cells and basophils -- immune system molecules that line your lungs, skin and mucous membranes.
As this occurs, the mast cells and basophils become inflamed and irritated, which then sparks the release of a wide range of biochemicals. The end result is one particular chemical known as histamine, which floods your tissues. When it does, blood vessels and tissues in your nose begin to dilate and swell, while sensitive nerve endings become highly irritated. And then, quite quickly, you have an "allergy attack."
"In the case of seasonal allergies, histamine would initiate the classic sneezing, wheezing and stuffy nose, along with itchy, red, watery eyes," Bassett says.
For many years, the treatment of seasonal allergies relied on preventing or reducing histamine production, as well as mast cell inflammation. While the treatments worked well, to get optimum relief they had to be administered before exposure because, once histamine production began it could not really be reversed.
However, the new anti-IgE treatments take an entirely different approach, working to help prevent the body from reacting to an allergen in the first place.
"An anti-IgE binds to IgE and ties it up, preventing it from activating and inflaming the mast cells," Rosenwasser says.
The body is "tricked" into believing there is no allergen present. So, it responds as if there were no allergy.
More importantly, anti-IgEs are not "allergen-specific." Theoretically, they can work to block almost any type of allergic reaction.
"It has promise in all allergic diseases," says Rosenwasser, "including drug and food allergies."
The good news is that the first anti-IgE medication -- a drug known as Xolair (omalizumab-RhuMAb-E25), manufactured by Genetech -- is expected to be approved by the U.S. Food and Drug Administration in time for the spring-summer allergy season.
The discouraging news is that it must be administered by your doctor, via injection, once or twice a month, which is expected to be costly. And since it was tested primarily in asthma patients, it's true effectiveness with seasonal allergies has not yet been fully determined.
With that in mind, unless your seasonal allergies are severe, doctors say you may want to wait a bit before you rush out and get that anti-IgE treatment.
"For those who have standard hay fever, which can be easily controlled by nasal steroids or an antihistamine, anti-IgE medication may not be economically feasible -- at least in the beginning," Rosenwasser says.
If, however, your allergies are severe, and particularly if you haven't found relief from available treatments, Xolair may be worth a try. Should it turn out to be extremely effective, it may become one of the "big guns" in allergy care, Rosenwasser says.
Besides Xolair, other IgE drugs are in development to help treat various types of allergies. Earlier this year, studies published in The New England Journal of Medicine showed how one anti-IgE medication reduced the life-threatening affects of a peanut allergy.
In addition, Rosenwasser and colleagues at the National Jewish Medical and Research Center are developing yet another allergy treatment called Anti CD23. It works by thwarting the connection between allergens and the immune system at an even earlier stage than the anti-IgE drugs, and similarly disrupting the sequence of allergic responses. This treatment could be available within several years.
More information
To learn more about all available treatments for allergies, visit The American Academy of Allergy, Asthma and Immunology. Or you can check with the National Library of Medicine.
SOURCES: Clifford Bassett, M.D., allergist and immunologist, New York University Medical Center, New York City; Lanny Rosenwasser, M.D., president, American Academy of Allergy, Asthma and Immunology, allergist and researcher, National Jewish Medical and Research Center, Denver
Copyright � 2003 ScoutNews, LLC. All rights reserved.
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