The Allergenic March - Adult Allergies

Hard to believe, but too much cleanliness may be to blame

If you never had allergies as a child but now find yourself affected bydust, dander, mold and pollen that leave you coughing, sneezing and wheezing,you might place the blame on too clean a home in childhood.

This Hygiene Hypothesis is one of the reasons allergists believe increasingnumbers of adults who have no childhood history of allergy are now experiencingadult-onset allergies.

Most of these sufferers grew up in a super clean world where germs weredestroyed as quickly as possible. Now we are learning that the idea of keepingchildren`s exposure to dirt and pollutants to a minimum may cause more harmthan good.

"Antibiotics and vaccines that protect children from life-threateningdiseases have undeniably saved many lives. But when a child`s immune system isnever exposed to some of these same infections, it can`t fully develop theability to combat all the allergens he will be bombarded with as anadult," according to Dr. Anju Peters, associate professor of medicine atNorthwestern Memorial Hospital.

When respiratory diseases began to surge the `90s, experts blamed it onincreases in air pollution. In Germany Dr. Erika Von Mutius began a study comparing therates of allergies in East and West Germany. Her hypothesis was that childrengrowing up in the poorer and less healthful cities of East Germany would suffer more from allergiesthan children in West Germany, with its cleaner and more modernenvironment.

When the two regions were reunified in 1999, she compared the disease ratesand found the results were the exact opposite of her hypothesis. Children inpolluted East Germanyhad lower allergic reactions and fewer cases of asthma than children in theWest.

Von Mutius was forced to abandon her original hypothesis. Her new hypothesisbased on her observations, today known as the Hygiene Hypothesis, is thatchildren who are around many other children or animals early in life areexposed to more microbes, and their immune system develop more tolerance forthe irritants that cause allergies and asthma.

A genetic predisposition is another trigger that can activate allergens inadults, said Dr. Michael Foggs, chief of Allergy and Immunology for AdvocateHealth Care.

"Allergies to specific allergens are not necessarily inherited, but thegeneral tendency to develop allergies can be traced back to your family. If oneof your parents has allergies, you have a much better chance of developingallergies, too," said Foggs.

Foggs also believes that many of the "new" allergies that afflictadults actually are a re-activation of childhood allergies. "The sneezing,wheezing and runny noses that were the reaction to pollen may have beenmisdiagnosed as the common cold," he said. "For some unknown reason,pollen and other allergens became dormant but something like a virus, acquiringa pet or moving to a new environment that contains more pollutants triggered anallergic response in the immune system.

"And, since repeated exposure to certain allergens can cause anallergic reaction, your age also has something to do with developing allergies.By the time you`re an adult, you`ve had more time to come in contact with dust,mold, dander and pollen," Foggs added. "Sometimes it takes long-termexposure to an allergen such as tree pollens before the person reaches his orher threshold and symptoms such as wheezing and shortness of breath begin toappear."

Still another theory that researchers are exploring is a correlation betweenthe increase in man-made chemicals and additives (used in processed foods tokeep them fresh and to enhance their flavor) as well as pesticides sprayed on fruitsand vegetables and the increase in adult onset allergies.

Over the years, we tend to put on weight. A recent study found women with a body mass index (BMI) of 30 or more had three times the risk of allergies compared to women with BMIs less than 20. The connection may be due to more fat cells, which release inflammatory chemicals that can contribute to allergies.

A significant proportion of adult-onset asthma is related to workplace exposure, accounting for 9-to-15 percent of all cases. Workplace stress can contribute to asthma in adults as well. Research scientist, Dr. Yacoub, studied adult onset asthma and found that patients with occupational asthma are highly anxious and many are chronically depressed.

There is an association between adult-onset asthma and Gastroesophageal reflux disease GERD, especially in those with wheezing that is worse at night, when supine, or after meals, and in those with no previous history of allergies. Studies have revealed that by treating the reflux in these patients there is an improvement in their respiratory symptoms and a decreased need for asthma medications.

Once you have been tested and know what allergens will trigger an allergicreaction, the basic treatment is avoidance. "If the allergen is airborne,keep your doors and windows closed and use air-conditioning with filters totrap the pollen. If the irritant is a particular food, cut it out of yourdiet," said Peters.