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April 13, 2000
The bright flowers, springy grass and fresh green trees of spring arent just pretty to look atthey also cause the runny noses, watery eyes, and other symptoms of allergies, which can lead to asthma attacks. Some allergic reactions and asthma attacks are life-threatening.
But help may soon be at hand for some of the 40 to 50 million Americans who suffer from allergies. A new medicine that can eliminate the substance in the body that causes allergies is on the way.
What causes allergies?
Allergic symptoms occur when the body overreacts to certain proteins in things like pollen, pet dander, and food. The body attacks these proteins, known as allergens, with a substance called IgE, a type of antibody which binds to the proteins. Once IgE has attached itself to an allergen it binds to special cells known as mast cells. When IgE and mast cells meet, the mast cells secrete a chemical called histamine, and it is histamine that tells the body to flush out what it sees as harmful invaders by causing inflamation and producing extra seretions. Because your nose, wind pipe and the skin around your eyes are lined with mast cells, coughing, sneezing, a running nose and tears are the hallmarks of allergy.
The effects of allergies: This man had just been mowing the lawn. footage: NY Presbyterian Sleep Disorders Center
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People who suffer from allergies like hayfever (also called seasonal rhinitis) and certain types of asthma have very high levels of IgE circulating in their body, which cause their symptoms. The new approach to treating allergies works by mopping up this extra IgE.
How would it work?
The trick that researchers have used is to fight the IgE antibody with another antibody, says James Li, MD, an expert on anti-IgE at the Mayo Clinic. In the laboratory, scientists created an antibody that attaches to IgE in the same way that IgE attaches to allergens. By attaching to IgE the synthetic antibody puts the troublesome molecule out of action, preventing it from reaching the mast cells and therefore relieving the sneezing, itching and wheezing.
Just as vaccines protect us against infectious diseases like polio, smallpox, and hepatitis, an anti IgE drug would protect allergy and asthma patients from allergic reactions and asthma attacks triggered by allergens. Regular injections of anti-IgE would keep the IgE at bay. "The most recently reported results show over 90 % decrease in the circulation of IgE," says Li.
Dr. Marianne Frieri, director of allergy and immunolgy at the Nassau County Medical Center in New York, is excited about the prospect of anti-IgE drugs. "By giving an anti-IgE, one is able to block the amount of circulating free IgE and help lower the symptoms."
Anti-IgE therapy wont be for everyone, however. "I think it would be for the more serious cases," says Frieri. "One can treat mild nasal allergy or asthma with standard environmental control, nasal sprays and tablets as well as other treatments that we use now." Also, further testing is needed before this new treatment for allergies will be approved for use in the United States.
Allergy myths and facts
Some dogs, like Chihuahuas, cause fewer allergy symptoms.
Its not the actual fur, but the protein in the fur, saliva and urine that cause allergic reactions. Avoiding exposure to these factors will help you avoid allergies.
Children will outgrow asthma.
Asthma symptoms do not necessarily fade as the child grows. Asthma is a chronic condition, and while some children experience fewer symptoms later on, others get worse.
Asthma is curable.
Asthma is a lifetime condition; there is no cure. However, with proper treatment, asthmatics can live a normal life with little impact on the quality of life.
Moving to the Southwest will cure asthma and allergies.
Although symptoms may subside at first, new allergies to local (and imported!) plants soon develop (the writer has first-hand knowledge of this).
Continuous exposure to pets will decrease allergic symptoms.
Your allergies will not go away by constantly petting Fido or Fluffy. The best means to decrease pet allergies is to remove the pet from your home. If the thought of banishing your beloved pet causes you hives, try keeping the pet out of your bedroom, bathe the pet twice a week to reduce the allergen levels, have a non-allergic family member brush the pet outside, and clean out the pets cage or litter box frequently.
Elsewhere on the web:
National Institutes of Health-Allergy and Infectious Disease