For years, Barbara Rosvold dreaded the coming of fall. While many people rejoiced at the end of the hot, muggy Maryland summer, Ms. Rosvold, 51, of Middletown, MD, cringed, for she knew that with the autumn colors came ragweed pollen--and the accompanying stuffy nose, itchy eyes and congestion of seasonal allergies. Even taking medication didn't help; although it eliminated the allergic symptoms, it left her tired and fuzzyheaded, a condition nearly as bad as the sneezing and stuffiness.

Ms. Rosvold is just one of an estimated 35 to 50 million Americans (1)--20 percent of the population--who suffer from seasonal allergic rhinitis or seasonal allergies. Overall, as many as 60 million Americans, or one in every five adults and children, have some form of allergy, which is the sixth leading chronic disease in the country. (1) The disease is far from just a minor inconvenience. Allergic rhinitis cost the United States $3.4 billion in 1993, of which $2.3 billion represents medications and $1.1 billion physician billing. Allergic rhinitis is gender neutral, affecting women at the same rate as men. (2) It's also species neutral: even dogs get allergies!

One worrisome trend is that the incidence of allergies and asthma--a complication of allergies--appears to be on the rise. Increased airborne pollutants, rising levels of indoor allergens due to better and tighter construction methods, poor ventilation (3) and even a growing insistence to be "too clean," the so-called hygiene hypothesis, are all possible causes. The hygiene theory holds that the infections you're exposed to as a child help your immune system "learn" how to behave; too little exposure, and it goes overboard when it encounters anything foreign, even normally harmless antigens, says Dean D. Metcalfe, MD, chief of the Laboratory of Allergic Diseases at the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health, Bethesda, MD.

What's An Allergy?

An allergy is a reaction of your immune system--your body's defense against invading agents such as bacteria and viruses--to normally harmless substances that don't cause problems for most people. These substances, which include pet dander, certain foods, molds and pollens, cause a false alarm reaction because your immune system treats them as invaders, generating large amounts of the disease-fighting protein immunoglobulin E, or IgE, a type of antibody. (2)

If you're allergy-prone, the first time you're exposed to an allergen, you begin to make large amounts of the corresponding IgE antibody. These IgE molecules attach to the surfaces of mast cells (in tissue) or basophils (in circulation). Mast cells are particularly plentiful in the lungs, skin, tongue and lining of the nose and intestinal tract, places where the outside of your body meets the inside, notes Dr. Metcalfe. "This activates the mast cells, and they spit out chemicals (including histamine, cytokines and leukotrienes) that go out into your tissues and cause the allergic response," he explains. That's the wheezing, sneezing, runny eyes and itching that are the hallmarks of allergies.

Blame Your Genes

Allergies can develop at any age, although heredity plays a key role in who develops them, (1) with genetic studies finding that 25 to 50 percent of children who have one allergic parent develop allergic rhinitis, asthma or both. While we don't "grow out" of allergies, they may decrease or go into temporary remission. (4)

But additional causes are under investigation. One study found that the age at which your mother began menstruating could affect whether or nor you have allergies. Researchers theorize that differences in a woman's estrogen levels--which play a role in the start of menstruation--somehow "programs" the fetus' immune system. (5) Another study found a correlation between complications during pregnancy (hemorrhage, preterm contractions, restricted growth of the uterus and insufficient placenta), the development of a child's immune and respiratory systems and an increased risk of asthma and allergic disorders. (6)

But a genetic predisposition is just part of the equation. You also need an environmental trigger--the allergen itself. Together, the two react like a lighted match on gasoline. For instance, says Dr. Metcalfe, you might be genetically predisposed to a birch pollen allergy. But, if you live in the Arizona desert, you'll never be exposed to birch pollen. Move to Scandinavia, however, and you may want to invest in a truckload of tissues.

Allergies as You Age

Marsha Shapiro, 35, grew up on the coast of Virginia and never suffered from allergies until she moved to Atlanta, GA, at age 22. During her first four falls and springs in the southern city, she experienced numerous sinus infections. Finally, her health care professional recognized a pattern. "You're allergic," he told her, and prescribed a steroidal nose spray and a prescription antihistamine. The sinus infections disappeared.

Ms. Shapiro's situation is not unusual. During the first year or two of life, children rarely develop allergic rhinitis. They're more prone to food allergies, particularly to milk and peanuts. That's probably because very young children aren't exposed much to the outdoors, says Wesley Burks, MD, professor of pediatrics and president, Arkansas Children's Hospital Research Foundation in Little Rock, AK. As they grow and have more exposure to both outside allergens (pollens, grasses) and indoor allergens (pet dander, dust mites, cockroach droppings) the allergies begin. Conversely, as children grow older and their immune system becomes better able to regulate the production of IgE, they may also grow out of certain food allergies, he says.

Puberty provides another impetus for the development of allergies, says Dr. Metcalfe. "Some people see their allergic reactions change with hormonal changes," he says, which is why some people may first develop allergies in their teenage years.

Additionally, if you've never been allergic to cats, even though you were around them growing up, and then suddenly develop an allergy to the kitten you bought for your new apartment, it could be that the level of exposure is finally large enough to trigger the allergic reaction, says Dr. Metcalfe.

Risks of Allergies

Allergic rhinitis is more than just a runny nose. In some people, the allergic response can lead to anaphylaxis or anaphylactic shock--a sudden and sometimes deadly drop in blood pressure that can potentially stop the heart or lead to complete closure of air passages, causing death by suffocation. (7)

More common is the development of sinusitis (inflammation of the sinuses) and asthma from untreated allergies. In fact, according to a 2002 survey, it appears the incidence of sinusitis is increasing. Forty-two percent of people surveyed reported having at least one sinus infection in the last 12 months, compared to 33 percent the previous year, and 61 percent of physicians reported diagnosing sinusitis in more than 30 percent of their patients who came in with cold or allergy symptoms. (8)

Asthma, a condition in which the airways of the lungs narrow, resulting in wheezing and problems breathing, affects up to 78 percent of those with allergies. (9) Overall, an estimated 14.9 million persons in 1995 had asthma, resulting in more than 1.5 million emergency department visits, about 500,000 hospitalizations, and more than 5,500 deaths. (10)

"The most important thing is that people not treat allergies as a trivial problem," says Dr. Metcalfe. "People that don't have allergies should listen to those who do, and understand that they're really miserable."

Diagnosing and Treating Allergies

To diagnose your allergies, health care professionals examine the inside of your nose, which often appears swollen and pale or bluish in those with allergies. They may also conduct a blood or skin test, looking for levels of IgE antibodies to particular allergens. "If you don't have the antibodies, then it's a good indication that you're not allergic," says Dr. Burks. If you do have them, "It doesn't mean you are allergic. If I have 100 kids who have a positive skin test to milk, less than half will actually be allergic to milk when they drink it."

Once diagnosed, allergic seasonal and perennial rhinitis are likely to be treated with a combination of medications, including:

* Antihistamines. Oral antihistamines counter the effects of histamines, chemicals released from mast cells and basophils, thus preventing allergic symptoms before they start. They help reduce itching, sneezing and runny nose, but do little for congestion. But they also cause a variety of annoying side effects, including sleepiness, delayed reaction times, attention problems and decreased memory.(1) Newer drugs, such as fexofenadine (Allegra), loratadine (Claritin) and cetirizine (Zyrtec), all taken in pill form, as well as the intranasal antihistamine azelastine (Astelin), and ketotifen, an antihistamine drop for your eyes, are less sedating and thus the treatment of choice.

* Topical nasal corticosteroids. This class of drugs, inhaled through the nose, is the most effective medication for controlling symptoms of allergic rhinitis, particularly in severe cases. (1) Specific medications include beclomethasone dipropionate (Beconase AQ), triamcinolone acetonide (Nasacort AQ) and fluticasone propionate (Flonase). These drugs are effective even when taken on an as-needed basis. (12)

* Cromolyn sodium (Nasalcrom). This nasal spray helps prevent allergic reactions from starting in some patients by preventing the release of chemicals like histamine.

* Decongestants. These medications, available over-the-counter or by prescription, include pseudoephedrine (Sudafed). They help relieve congestion, swelling, excess secretions and discomfort in the sinus areas, but they may cause insomnia, loss of appetite or nervousness. (2)

* Immunotherapy. Also called allergy vaccine therapy, this treatment consists of a series of injections given over time. You receive injections of increasing concentrations of the allergen to which you're sensitive, which reduces the amount of antibodies in your blood, prompting your body to make a different protective antibody. (2)

New Treatments on the Horizon

In the coming years, health care professionals should have a host of new treatments at their fingertips to treat allergies, thanks in part to genetic engineering. For instance, a monoclonal anti-IgE antibody injection therapy now in clinical testing, called omalizumab, works by blocking IgE before it can bind to the mast cell, thus interrupting the trigger that releases inflammatory chemicals such as histamine, which causes allergy symptoms. In clinical tests, omalizumab greatly reduced the need for inhaled corticosteroids in both children and adults with asthma, and most asthmatic children were able to stop taking these medications while receiving anti-IgE. (13, 14)

More people are also expected to begin using non-sedating medications for their allergies, as the popular prescription antihistamine Claritin may be sold over-the-counter later this year. (15)

Scientists are also exploring how air pollution worsens allergies, particularly with population-based studies suggesting that environmental factors play an important role in the increasing incidence of allergic disease. For instance, scientists are examining how compounds in diesel exhaust affect allergies, and evaluating new ways to control environmental exposures to allergens and pollutants to prevent allergic diseases.

Resources

My House is Killing Me: The Home Guide for Families with Allergies and Asthma, by Jeffrey C. May and Jonathan M. Samet (Johns Hopkins University Press, 2001).

All Allergy Net

http://www.allallergy.net

This site serves as a gateway to allergy sites on the Web.

Food Allergy and Anaphylaxis Network

10400 Eaton Place, Suite 107

Fairfax, VA 22030-2208

1-800-929-4040

http://www.foodallergy.com

Works to raise public awareness and advance research on behalf of all those affected by food allergies and anaphylaxis. Site provides consumer information.

National institute of Allergy and Infectious Diseases (NIAID)

Building 31, Room 7A-50

31 Center Drive MSC 2520

Bethesda, MD 20892-2520

301-496-2263

http://www.niaid.nih.gov

Provides print and online consumer resources about asthma and allergies.

Allergy and Asthma Journal Watch

http://www.allergyjournals.com

This site provides overviews of journal articles about allergies and asthma.

What to Do if Someone is Having a Severe Asthmatic Attack

If you are with someone who suddenly has a severe asthma attack, follow these guidelines from the American Medical Association: (11)

* Know the signs of trouble: the person stopped playing or working and can't start again; they're struggling to breathe; they have trouble walking or talking

* Stay calm and relaxed

* Remove the person from the allergy trigger (perfume, overheated room, pollen, etc.)

* Find the person's bronchodilator (check purse or pockets) and administer a dose

* Call 911 if the person is having trouble breathing or his or her lips or fingernails are blue

Common Allergens

These common allergens make many people miserable:

* Ragweed. This common weed flourishes along roadsides and throughout North America.

* Dust mites. These microscopic, sightless arthropods are natural inhabitants of indoor environments. Their droppings are the most common trigger of perennial allergy and asthma symptoms, especially in humid regions where dust mites thrive. (16)

* Cockroaches. Between 17 and 41 percent of children and adults are allergic to cockroaches, primarily to their droppings. (17)

* Pets. Allergic pet owners suffer from reactions to their pet's dander, skin flakes, saliva and urine; hair or fur can also collect pollens, mold spores and other outdoor allergens.

* Molds. Contrary to popular belief, it is not at all clear that allergies to fungi (molds) are increasing, says James Bonner, MD, professor of medicine in the Department of Pulmonary and Critical Care Medicine at the University of Alabama at Birmingham. And, he notes, there's very little evidence that fungi in homes produce toxins capable of causing human disease.

Food Allergens: Know Where They're Hiding

You know food allergies have hit the mainstream when they wind up in a story in the Wall Street Journal headlined, "Dinner Parties Become Ordeals as Allergies, Food Fears, Rise." (18)

Yet while fears may be rising, food allergies themselves may nor be rising at the moment, says Dean D. Metcalfe, MD, chief of the Laboratory of Allergic Diseases at the National Institute of Allergy and Infectious Diseases. Instead, it may be that more attention is being paid to them. Many people also confuse a food intolerance, such as lactose intolerance, in which dairy products cause gastrointestinal upsets, (19) with a true allergy. In a true allergy, your immune system recognizes an allergen in the food--usually a protein--as a foreign invader, and produces antibodies to halt the "invasion," unleashing a cascade of chemicals that causes such symptoms as swelling of the lips, stomach cramps, vomiting, diarrhea, hives, rashes or eczema and wheezing or breathing problems. True food allergies affect more than six million Americans, killing about 100 a year. (20,21)

The most common food allergens are milk, egg, peanut, wheat, soy, shellfish, fish and tree nuts, says Wesley Burks, MD, professor of pediatrics and president of the Arkansas Children's Hospital Research Foundation. "The foods you become sensitive to are the ones you're fed early in life," he says, which may be one reason breastfed children develop fewer food allergies.

There is no treatment for food allergies, says Dr. Burks. You simply have to avoid the offending food. "And that's not always possible because foods are often contaminated with other foods," he says. For instance, even a turkey sandwich prepared on the same counter as a peanut butter sandwich may pick up enough peanut "dust" to cause an allergic reaction in someone sensitive to peanuts. Plus, as the amount of processed foods we eat--which often contain "hidden" ingredients that may pose allergic threats--grows, the risk to those with food allergies increases. Consider that 28 percent of callers to a food allergy awareness organization reported experiencing allergic reactions to "safe foods" that were later found to contain unlabeled food allergens. (21)

The greatest danger with food allergies is anaphylaxis, which can produce life-threatening symptoms in as little as one to 15 minutes. That's why health care professionals recommend that if you have a food allergy, you carry an Ana-Kit or an EpiPen with you, devices for injecting epinephrine, a synthetic version of the naturally occurring hormone, adrenaline, which can reverse anaphylactic shock. (19)

Researchers are trying to develop immunotherapy treatment--allergy shots-- for food allergies just as they've done for some airborne allergies, Dr. Burks says. And new genetically engineered anti-IgE therapies for nasal allergies are also being tested for food allergies, he says.

Spotting Hidden Food Allergens

The Food Allergy and Anaphylaxis Network (see Resources, p.4) urges those with food allergies to be aware of these common hiding places for food allergens:

* Milk

Delicatessen meat slicers are frequently used for both meat and cheese products. Casein, a milk protein, is found in some brands of canned tuna fish, as well as non-dairy products. Casein also is used as a binder in some meat products.

* Eggs

Eggs may be used to create the foam or milk topping on specialty coffee drinks and are used in some bar drinks. Some commercial brands of egg substitutes contain egg whites.

Most commercially processed cooked pastas contain egg or are processed on equipment shared with egg-containing pastas.

* Peanuts

Arachis oil is peanut oil.

African, Chinese, Indonesian, Mexican, Thai and Vietnamese dishes often contain peanuts, or are contaminated with peanuts during preparation of these types of meals.

Foods sold in bakeries and ice cream shops often are in contact with peanuts.

AGES & STAGES

Hormones, Allergies and Asthma

"It's well documented that hormones make allergies worse," says Gail G. Shapiro, MD, clinical professor in the Division of Allergy at the Children's Hospital and Medical Center in Seattle.

That could explain why women are nearly twice as likely as men (9.1 vs. 5.1 percent) (23) to have asthma, and why, from the ages of 20 to 50, women outnumber men three to one in asthma-related hospital admissions. (24)

In fact, up to 40 percent of women with asthma find their symptoms worsen just before and during menstruation. (25) "It's probably related to progesterone levels," says Dr. Shapiro. Progesterone, a female hormone, rises sharply and then drops abruptly towards the end of the menstrual cycle, just before menstruation begins, although scientists don't understand exactly how progesterone affects asthma.

Asthma During Pregnancy

Asthma may also get worse or improve during pregnancy, says Michael Schatz, MD, chief of the Allergy Department at Kaiser-Permanente Medical Center in San Diego. No one really knows why these changes occur, he says. But such things as increased stress, infections, increased production of inflammatory chemicals known as prostaglandins and increased resistance to the steroids often used to treat asthma are all reasons why a pregnant woman's asthma may get worse. Of course, that doesn't explain why some women's asthma improves.

If you have asthma, you should still be able to have a safe and normal pregnancy as long as you keep your asthma under control. Control is crucial, though, because asthma attacks cause a decrease in blood oxygen levels, which can affect the amount of oxygen your baby receives. (26) There's also some data that suggests that poorly controlled asthma may affect the size of the baby, says James Bonner, MD, professor of medicine in the Department of Pulmonary and Critical Care Medicine at the University of Alabama. Because it's so important to control asthma during pregnancy, he says, health care professionals are more likely to prescribe medications. However, only you and your health care team can compare the risks of the drug to the baby against the benefits for you and the baby.

The American College of Allergy, Asthma and Immunology and the American College of Obstetricians and Gynecologists suggests the following regarding asthma and allergy medications: (27)

* You may continue with your allergy shots while you're pregnant, but don't start them for the first time while pregnant.

* The short-acting bronchodilators such as Albuterol, Ventolin and Proventil are permissible, while ipratropium (Atrovent) could be used if necessary.

* Inhaled corticosteroids, especially beclomethasone (Vanceril or Beclovent) or budesonide (Pulmicort) are the drugs of choice for persistent asthma not controlled by cromolyn or nedocromil.

* Chiorpheniramine (Chlortirmeton) and tripellanamine (Pyribenzamine) are the antihistamines of choice mainly because, at the time the medical groups drafted these recommendations, there wasn't enough information about the use of newer antihistamines like Claritin during pregnancy.

Although pregnant women have used the decongestant pseudoephedrine (Sudafed) for years, recent reports suggest a slight increase in abdominal wall defects in newborns, so it's suggested women avoid oral decongestants during the first trimester.

One of the best treatments for congestion may be simple saline irrigation -- washing out your nose with salt water to relieve congestion. (28)

Medications During Nursing

Nearly all medications, including asthma and allergy medications, enter your breast milk, though infants are exposed to very minute amounts. In general, it's best to nurse your baby before taking the medicine, and then don't nurse again for three or four hours. (26)

Post-Menopausal Allergies

As women age, many find their allergies disappear. "But this isn't specifically related to menopause," cautions Dr. Shapiro. "It's probably that people tend to produce less IgE as they age, and that's related to allergies."

References

(1.) American Academy of Allergies, Asthma & Immunology, http://www.aaaai.org

(2.) "Allergies." National Women's Health Resource Center. http://www.healthywomen.org

(3.) Hayden, ML. "Allergic Rhinitis: A Growing Primary care challenge." J Am Acad Nurse Pract Dec 2001; 13(12):545-51.

(4.) Gonsior, E. "Understanding the Allergic Airway Syndrome." Allergy & Asthma Advocate. Winter 2001.

(5.) Xu, B., Jarvelin, M.R., Hartikainen, A.L. and Pekkanen, J. "Maternal Age at Menarche and Atopy Among Offspring at the Age of 31 Years." Thorax. 2000 Aug; 55(8):691-3.

(6.) Nafstad, P. and Magnus, P., Jaakkola J.J. "Risk of childhood Asthma and Allergic Rhinitis In Relation to Pregnancy complications." J Allergy clin Immunol. 2000 Nov; 106(5):867-73.

(7.) "Understanding the Immune System." National Institutes of Health. http://rex.nci.nih.gov

(8.) "Allergies and colds May Lead to Sinus Infection," [press release]; West Haven, Ct. American Academy of Otolaryngology, Head and Neck Surgery. March 21, 2002.

(9.) "Asthma." American Academy of Allergy, Asthma & Immunology. http://www.aaaai.org

(10.) "Asthma Statistics." National Blood, Heart and Lung Institute. http://www.nhlbi.nih.gov

(11.) "Managing Asthma Episodes." American Medical Association, 1997. http://www.medem.cam

(12.) Kaszuba, S.M., Baroody, F.M., deTineo, M., Haney, L., Blair, C. and Naclerio, R.M. "Superiority of An Intranasal corticosteroid compared with an Oral Antihistamine in the As-Needed Treatment of Seasonal Allergic Rhinitis."

Arch Intern Med. 2001 Nov 26; 161(21):2581-7.

(13.) Allergy & Asthma Advocate: Winter 2001.

(14.) Berger, W.E. "Monoclonal Anti-IgE Antibody: A novel Therapy for Allergic Airways Disease." Ann Allergy Asthma Immunol 2002;88:152-161.

(15.) "Claritin Going Over the Counter." Associated Press. February 14, 2002.

(16.) White, M. "Allergy Proofing Your Home." Allergy & Asthma Advocate. Winter 2000.

(17.) Zitt, M. "Cockroach Allergy: A Major Cause of Asthma." Allergy & Asthma Advocate. Fall 2001.

(18.) "Dinner Parties Become Ordeals as Allergies, Food Fears, Rise." Elizabeth Bernstein. Wall Street Journal. May 11, 2001.

(19.) "Food Allergies Rare But Risky." FDA consumer. U.S. Food and Drug Administration. May 1994.

(20.) American Academy of Allergy, Asthma & Immunology. http//www. aaai.org

(21.) "Improved Food Labeling Needed to Reduce Allergic Reactions," (press release); Milwaukee: American Academy of Allergy, Asthma & Immunology, Sept. 17, 2001.

(22.) Food and Anaphylactic Allergy Network. http://www.foodallergy.org

(23.) "Asthma in Women." Women's Health in Primary care, February 2002; 5(2).

(24.) "Women and Allergies." National Women's Health Information center. http://www.4woman.gov

(25.) Tan, K.S. "Premenstrual Asthma: Epidemiology, Pathogenesis and Treatment." Drugs 2001;61(14):2079-86.

(26.) "When Pregnancy is complicated by Allergies and Asthma." American college of Allergy, Asthma & Immunology. http://www.aaai.org

(27.) "The Use of Newer Asthma and Allergy Medications During Pregnancy." American college of Obstetricians and Gynecologists (ACOG) and American college of Allergy, Asthma and Immunology (ACAAI). Ann Allergy Asthma Immunol. 2000 May; 84(5):475-80.

(28.) Keen, Peggy. "Hormonal Influences on common Health Problems in Women." http://www.medscape.com