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http://www.omniture.com --> Sections Home Page Local News AP News Archives Business Classifieds Event Calendar Forums Life Opinion Obituaries Photo Gallery Since We Asked Sports Tempo Weather Special Coverage 2006 Britt Festivals --> Shop Our Valley AutoFinder HomeFinder JobFinder Search Our Valley Special Sections Homelife Magazine Joy Magazine Readers Choice 2006 Oregon Golf Info Oregon Wine Info Our Valley Other Publications Local Links Ashland News eSouthernOregon Newspapers In Education Personals Moving Here Movie Listings TV Listings Volunteer Customer Service Advertise With Us Media Kit Place Classified Ad Contact Us FAQ's Home Delivery Site Map --> Email Story to a Friend August 28, 2006 Allergies evolve along with their many sufferers Do allergies change with age? I seem to have more problems now than when I was younger. Sandy T., Medford Lots of body functions change as we grow older, so it should come as no surprise that allergies actually do change with age, says Dr. Ed Kerwin, a Medford allergist. Kerwin says many people start out with no allergies at all and become more sensitive as teenagers and young adults, eventually joining the ranks of the 20 to 30 percent of us who are troubled by some kind of allergy. The list of allergens (the substances that cause allergic reactions) tends to increase as we age, too. People who are sensitive to animal dander or pollen as children may become more vulnerable to molds, dust mites and other particles in adulthood. Allergies happen when the human immune system overreacts to a substance that is usually harmless, such as microscopic pollen particles in the air. The immune system produces an antibody to fight the pollen, and the antibodies attach to a specialized blood cell called a mast cell. The mast cells burst, releasing chemicals such as histamine. Histamine, in turn, causes the sneezing and runny nose that are the most common symptoms of what doctors call "allergic rhinitis" and the rest of us call "hay fever" or just plain "allergies." Advertisement In rural Southern Oregon, pollens from field grasses (those that are cut for hay or grow wild) are one of the most common sources of allergies. Mowed lawns don't grow tall enough to make pollens, but there is so much grass pollen in the air in spring and summer that even people who live in town can develop symptoms. Kerwin says some people who have never had allergies suddenly find they're sensitive when they move to a place like the Rogue Valley, where there are lots of grass pollens. People who have allergies can be generally divided into three equal groups: those who are allergic to grass pollens during the height of summer; those who are allergic to grass pollens in summer and dust mites and mold in winter; and those who are allergic to other things, such as foods. Scientists are still trying to understand why some people develop allergies and others don't, and why the incidence of allergies has increased over the past few decades. Back in 1900 only about 5 percent of U.S. residents were troubled by allergies. One of the explanations being considered is the "hygiene hypothesis," which suggests that modern hyper-clean environments actually make people more allergy-prone. "One hundred years ago little babies would be exposed to much more dust and dirt," Kerwin says. "When your immune system is exposed to dust and pollens, your T-cells (the red blood cells that turn on antibody production) learn to be more tolerant. "If you live in a city, it's that occasional periodic exposure that creates allergies," he says. Kerwin says a growing body of evidence seems to support this hypothesis. Pacific Island people who had little history of allergies when they lived in primitive villages have more problems with allergies now that they live in modern houses that reduce their exposure to dust and dirt. For those who are sensitive, the frequency of exposure to an allergen seems to play a role in the intensity of the reaction. For the 30 percent of us who are allergic to poison oak, for example, each additional exposure to the toxic oils seems to trigger a stronger reaction. "With repeated occasional exposures, people become more and more allergic," Kerwin says. Sensitivity to bee stings can increase in the same way. The initial sting might trigger only a small response such as redness, swelling and itching. Each additional sting may produce a stronger reaction as well as other symptoms (lightheadedness, hives). Allergy sufferers sometimes find their symptoms moderate as they ease into old age. Kerwin says the immune system, like other parts of the body, becomes less vigorous toward the end of life, and people in their 70s and 80s sometimes find their allergies less troubling than they were in earlier years. Call Bill Kettler with your medical questions at 776-4492, or e-mail them to [email protected] or send them to: Mail Tribune, Ask Your Doctors, P.O. Box 1108, Medford OR 97501. Would you like to respond to this story? If so Click Here to visit our forums. Advertisement Copyright © 1997-2006 Mail Tribune, Inc. All rights reserved. Privacy Policy | Terms & Conditions | Website Feedback online casinos news Home Security Systems California Casinos Men's Clothing Southern Oregon Loans --> GMAT Prep Fundraisers Send Flowers Texas Electric Choice Entertainment Guide --> Casinos Canada Trunks, Footlocker Online Casino Reviews