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

If you never had allergies as a child but now find yourself affected by dust, dander, mould 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 increasing numbers of adults who have no childhood history of allergy are now experiencing adult-onset allergies.

Most of these sufferers grew up in a super clean world where germs were destroyed as quickly as possible. Now we are learning that the idea of keeping children’s exposure to dirt and pollutants to a minimum may cause more harm than good.

“Antibiotics and vaccines that protect children from life-threatening diseases have undeniably saved many lives. But when a child’s immune system is never exposed to some of these same infections, it can’t fully develop the ability to combat all the allergens he will be bombarded with as an adult,” according to Dr. Anju Peters, associate professor of medicine at North western Memorial Hospital.

When respiratory diseases began to surge the ’90s, experts blamed it on increases in air pollution. In Germany Dr. Erika Von Mutius began a study comparing the rates of allergies in East and West Germany. Her hypothesis was that childre growing up in the poorer and less healthful cities of East Germany would suffer more from allergies than children in West Germany, with its cleaner and more modern environment.

When the two regions were reunified in 1999, she compared the disease rates and found the results were the exact opposite of her hypothesis. Children in polluted East Germany had lower allergic reactions and fewer cases of asthma than children in the West.

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

A genetic predisposition is another trigger that can activate allergens in adults, said Dr. Michael Foggs, chief of Allergy and Immunology for Advocate Health Care.

“Allergies to specific allergens are not necessarily inherited, but the general tendency to develop allergies can be traced back to your family. If one of your parents has allergies, you have a much better chance of developing allergies, too,” said Foggs.

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

“And, since repeated exposure to certain allergens can cause an allergic 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-term exposure to an allergen such as tree pollens before the person reaches his orher threshold and symptoms such as wheezing and shortness of breath begin to appear.”

Still another theory that researchers are exploring is a correlation between the increase in man-made chemicals and additives (used in processed foods to keep them fresh and to enhance their flavour) as well as pesticides sprayed on fruits and 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 allergic reaction, the basic treatment is avoidance. “If the allergen is airborne, keep your doors and windows closed and use air-conditioning with filters to trap the pollen. If the irritant is a particular food, cut it out of your diet,” said Peters.