What is an allergy?

An allergy is a specific immunologic reaction to a normally harmless substance, one that does not bother most people. People with allergies are often sensitive to more than one substance. Common allergens that cause allergic reactions include seasonal, outdoor allergens like tree, grass, and weed pollen, and year-round indoor allergens including dust particles, animal dander, and indoor mold.

In some people, medicines, insect venom, and foods may also cause allergic reactions. See your doctor or healthcare provider promptly if you suspect you are having an allergic reaction to these substances.

Why are some people allergic and others not?

It may be all in the family, after all. Scientists and researchers believe that people inherit a tendency to be allergic, although not to any specific allergen. Children are much more likely to develop allergies if their parents have allergies. If you are allergic, your child has a 25% chance of developing allergies. If both you and your spouse have allergies, the chances rise to 75%. So check with your parents, grandparents, and other family members to see if they have allergies, too.

Exposure to allergens at certain times when the body's defenses are lowered or weakened, such as after a viral infection, during puberty, or during pregnancy, also seems to contribute to the development of allergies.

Interestingly, people with year-round (perennial) allergies commonly develop the problem as adults, and are more likely to be women than men. Symptoms can lessen as you get older, but they rarely completely disappear without treatment.

What is an allergic reaction?

Normally, your immune system protects you against invading agents such as bacteria and viruses. If you have allergies, otherwise harmless allergens (allergy-producing substances) cause your body to react as if they were dangerous invaders. In effect, your immune system is responding to a false alarm.

When you first come into contact with an allergen, your immune system treats the allergen as an invader and mobilizes an attack. The immune system does this by generating large amounts of a type of antibody (a disease-fighting protein) specific to the particular allergen you're allergic to. (Nonallergic people produce only small amounts of these antibodies.) In the case of pollen allergy, the antibody is specific for each type of pollen: one antibody may be produced to react against oak pollen and another against ragweed pollen, for example.

This antibody attaches itself to certain cells in your body. The next time you come into contact with the allergen, the allergen attaches to the antibody like a key fitting into a lock, causing the release of powerful inflammatory chemicals, including histamine. These chemicals move into various parts of your body, such as your respiratory system, to cause allergy symptoms including runny nose, itchy eyes, and sneezing, among others.

Allergy glossary:
Familiarizing yourself with the following terms can make talking to your doctor about your allergies easier.

Allergen: Any substance that leads to allergies by starting an immune response.

Allergic rhinitis: A medical term that describes inflammation of the nasal passages. Symptoms of allergic rhinitis include sneezing, congestion, runny nose, and itchiness in the nose, throat, eyes, and ears. Sometimes called hay fever.

Antihistamine: A medication that blocks the action of histamine.

Histamine: A powerful inflammatory chemical that moves into various parts of the body, such as the respiratory system, to cause allergy symptoms.

Hives (urticaria): A skin allergy that produces swelling, redness, and itching. It may be caused by drug allergy, insect stings or bites, or by eating certain foods, particularly eggs, shellfish, nuts, or fruits. Often, the cause of hives is unknown ("idiopathic").

Year-round (perennial) allergic rhinitis: Perennial allergic rhinitis describes allergies that occur year-round and cause symptoms throughout the year. Many of the allergens causing these year-round symptoms are found indoors, including dust mites, animal dander from dogs, cats, and other furry pets, and molds found in damp humid areas like bathrooms and basements.

Seasonal allergic rhinitis: This term describes allergies that occur only during outdoor seasons. The most common seasonal allergens include airborne tree, grass, and weed pollens, and outdoor molds that grow in moist, damp areas.

An estimated 20 to 25 million people in the United States who suffer from allergies to pets. For one out of every five of these people, an allergic reaction to animals can trigger an attack of asthma, a disorder marked by coughing, wheezing, and difficulty breathing.

Not long ago, doctors who specialize in allergies and pulmonary diseases had one piece of advice for such sufferers: the pet must go. But times have changed, few people will part with a pet even if the allergy in question causes potentially serious health problems. "Given the feelings people have about their cats and dogs, they'd just as soon get rid of their doctor," remarks Oren P, Schaefer, an allergist and assistant professor of medicine at the University of Massachusetts Medical School in Worcester. This intense commitment has prompted doctors to reconsider how best to treat their patients, and they have come up with strategies that include medications, household modifications, or both.

Nearly all allergies to pets are caused by a glandular protein that the animal secretes onto its skin.
As the skin is shed, tiny flakes, known as dander, (DUST) float around in the air and stick to walls, carpets, furniture, and clothing.

From there, they can easily make their way into noses, eyes, and throats. A person also can have an allergic reaction to the protein in a pet's saliva or urine. Contrary to widespread belief, a pet's fur or hair itself is not the cause of the problems. "The animal's hair may get a coating of the protein as well, but it's the skin flakes, because they are so tiny, that go everywhere and concentrate a Hundred fold over what the animal carries," explains John S. Sullivan, an allergist who practices at the Fallon Clinic in Leominster, Massachusetts.

Schaefer and Sullivan both say that the most effective way to minimize an allergic reaction is to keep a pet outdoors at all times. Since most people would consider this poor pet care, at the least they recommend barring the dog or cat from the bedroom. Another recommendation -- one that is likely to raise a howl of protest from allergy-plagued animal lovers -- is to handle the pet as little as possible. Meanwhile, sufferers can take a few simple steps that, put together, are likely to remove up to 85 percent of the dander from the home.

Much of the carpeting, a magnet for the miniscule flakes of skin, could be removed, and what remains should be vacuumed through a filter that returns clean exhaust to the air. Schaefer suggests that vaccuming be done just once a week because the suction kicks up the dander. "I recommend getting someone else to do it, which makes a lot of my patients happy," he says. The doctors also recommend that upholstered furniture, another handy reservoir for dander, be removed and replaced with chairs and sofas covered with leather or vinyl. The air itself can be cleansed with a high-efficiency filter that pulls small particles of dander from the atomosphere, they advise. Finally, a cat or dog will cause far less allergic reacion if it's washed once a week. "People laugh about it when it's a cat," says Schaefer, "but a good grooming removes the protein on the surface."

Can attest to the efficacy of the grooming remedy. The story of a client who was desperate for help because she had developed an allergy to her sheltie. "Can you shave her down?" the woman asked. The groomer replied that she could but the dog would not look particularly pretty. "It's my last chance to keep her," the woman said. The sheltie's shampoo and close clip did the job. The groomer now grooms and trims the dog regularly, and the owner's allergic reaction is at a livable level.

Dogs and cats are not alone in producing allergic reactions in humans, the experts warn. Many people who are inclined toward allergies become sensitive to more than one thing in their daily environment -- and that can include the pet parakeet or canary. Sullivan sees more patients who cough and sneeze in the presence of ferrets now that the small, furry critters have become popular companions. But of all the members of the animal kingdom, it is cats that engender the most widespread allergic reaction in people. No one knows just why; doctors theorize that cats tend to live indoors and find their way around every nook and cranny of the home, leaving behind a residue of dander wherever they go.

Sarah Miner, a student at the University of Colorado, has been allergic to her feline, R-C., since she was a little girl. She sneezes, her skin itches, and her eyes become red and watery. Despite her doctor's prodding, she has never considered parting with him, and they've been together for 16 years now. "It's hard for someone else to understand, but he's just a really important part of my life," she says.

Doctors prescribe a variety of medications to make life more tolerable for people with annoying symptoms. While most can handle there reaction to dogs without help from a steady dosage of pills. He treats a teenager who takes five medications a day so that he can tolerate his cat. But the doctor understands. "For many people," he says, "the animal provides emotional support, companionship, and security. That's worth anything."

Hypoallergenic Breeds

Just one look, and you'll want to knit this little dog a sweater. The American hairless terrier is being touted in some quarters as the perfect companion for the allergic. Can it be true?

When it comes right down to it, even a Web site devoted the impish-looking and relatively rare canine tends to equivocate: "Animal lovers with allergies say they really are man's best friend because they almost never cause allergic reactions."

Doctors who specialize in treating allergies and pulmonary diseases might well chuckle at the statement. Asked if there is a type of dog or cat that triggers no reaction whatsoever in an allergic human, physician John S. Sullivan quips, "A ceramic one."

A person sensitive to dog or cat dander is reacting to a protein that coats the skin and gets into the eyes, nose, and throat as the tiny particles flake off. One breed, or one individual animal, may produce less dander than another, but even the hairless varieties shed the protein-coated particles. Sullivan, who treats patients at the Fallon clinic in Leominster, Massachusetts, explains that the amount of dander it takes to cause immediate coldlike symptoms or asthma attacks is different for each allergy sufferer. If the level is below that threshold, there may be no obvious reaction. But even without overt symptoms, an allergic human often experiences a subtle reaction when constantly exposed to a pet, he says. For some, it can become difficult to tolerate cold air or exercise.

"It's such an emotional issue," Sullivan notes. "They claim the animal doesn't bother them, but by sharing their life with the animal, it sensitizes them more."

Nonetheless, animal lovers will not be denied, and some are certain that they have found the answer. The hairless breeds -- among them the exotic sphinx cat and the rare Peruvian Inca orchid, Inca hairless, and Mexican hairless dogs -- have gained a reputation as "nonallergenic" pets. Frank Baylis, a breeder of show dogs who lives in Mount Olive, Virginia, remembers letting an allergic eight-year-old boy test his tolerance of a hairless Chinese crested, which sports a leonine mane and tail but has only soft skin on its body. "He held Ernie in his lap and played with him and had no allergic reaction," says Baylis. "Normally, by that time he would not have been able to breathe."

Certain other dogs and cats that do sport hair or fur also are widely thought to be kind to the allergic. Lynn Boucher coughs and sneezes around most of the cats and dogs she bathes and clips in her grooming business in West Brookfield, Massacusetts, yet maintains that she has no allergic reaction to her two pet poodles. Others swear by the soft-coated wheaten terrier, the Bichon Frise, the Tibetan terrier, the wire fox terrier, and the Maltese.

Those who cotton to cats also seek that special kind of companion. Sarah Miner is severely allergic to her cat, R.C., who has been part of her life for 16 years. Yet she wanted to get a companion for R.C., and she knew that she would have a stronger allergic reaction to certain felines. So she toured shelter after shelter in Boulder, where she attends the University of Colorado, nuzzling cats large and small, long-coated and short-coated, until she found a small one, of no particular breed, that did not make her eyes water or her skin itch.

Advice from Your Allergist...Pet Allergy

More than 70 percent of U.S. households have a dog or cat. Pets provide companionship, security and a sense of comfort. Children often learn responsibility and lessons about life and death from pets. However, people with allergies should be cautious in deciding what type of pet they can safely bring into their home.

Pet exposure may cause sneezing and wheezing. An estimated 10 percent of the population may be allergic to animals. A higher rate of 20 to 30 percent of individuals with asthma have pet allergies.

Pets can cause problems to allergic patients in several ways. Their dander, or skin flakes, as well as their saliva and urine, can cause an allergic reaction. The animal hair is not considered to be a very significant allergen. However, the hair or fur can collect pollen, dust, mold and other allergens.

What are the most common pets? The most common household pets are dogs, cats, birds, hamsters, rabbits, mice, gerbils, rats and guinea pigs. Larger animals such as horses, goats, cows, chickens, ducks and geese, even though kept outdoors, can also cause problems as pets.

The number of pets in the United States is estimated at more than 100,000,000. This large number also increases the likelihood of accidental exposure to animals by the allergic patient when visiting homes, farms, etc. Both feathers and the droppings from birds, another common pet, can increase the allergen exposure. The allergic patient should not use feather pillows or down comforters. If a feather pillow is used, it should be encased in plastic. An encasing with a zipper is recommended, so none of the feathers can escape.

Bird droppings can be a source of bacteria, dust, fungi and mold. This also applies to the droppings of other caged pets, such as gerbils, hamsters and mice.

What do allergists recommend?

The best types of pets for an allergic patient are pets that don't have hair or fur, shed dander, or produce excrement that creates allergic problems. Tropical fish are ideal, but very large aquariums could add to the humidity in a room, which could result in an increase of molds and house dust mites.

A frequent misconception is that shorthaired animals cause fewer problems. It is the dander (skin scales) that causes the most significant allergic reactions - not the length or amount of hair on the pet. As stated previously, allergens are also found in the pet's saliva and urine. In addition, dogs have been reported to cause acute symptoms of allergic conjunctivitis, or inflammation of the eye, and hay fever after running through fields and then coming back into contact with their owners.

Those pets that are known to cause significant allergic reactions should be removed from the home of the allergic patient to avoid possible progression of symptoms. A "trial" Removal of a pet for a few days or even weeks may be of little value since an average of 20 weeks is required for allergen levels to reach levels found in homes without pets.

Can pet allergies be managed?

If the family is unwilling to remove the pet, it should at least be kept out of the patient's bedroom and, if possible, outdoors. Allergic individuals should not pet, hug or kiss their pets because of the allergens on the animal's fur or saliva.

Indoor pets should be restricted to as few rooms in the home as possible. Isolating the pet to one room, however, will not limit the allergens to that room. Air currents from forced-air heating and air-conditioning will spread the allergens throughout the house. Homes with forced-air heating and/or air-conditioning may be fitted with a central air cleaner. This may remove significant amounts of pet allergens from the home. The air cleaner should be used at least four hours per day.

The use of heating and air-conditioning filters and HEPA (High Efficiency Particulate Arresting) filters as well as vacuuming carpets, cleaning walls and washing the pet with water are all ways of reducing exposure to the pet allergen. Vacuum cleaners with HEPA filters are now available. However, in a patient with severe symptoms resulting from animal dander exposure, a HEPA filter is not an effective solution.

Litter boxes should be placed in an area unconnected to the air supply for the rest of the home, and should be avoided by the allergic patient.

Some allergic patients may have severe reactions, such as wheezing and shortness of breath, after exposure to certain pets. Also, a chronic, slowly progressive feeling of shortness of breath, loss of energy and feeling of fatigue can result from long-term exposure to birds and their droppings. This type of disease is known as hypersensitivity pneumonitis and can result in severe disability. In the event of these severe cases, removal of the offending animal is mandatory.

How are pet allergies diagnosed?

The avid pet owner may claim that exposure to his or her pet does not cause their allergy symptoms. This, however, should be viewed skeptically, since pet ownership is an emotionally charged subject. Also, many allergic pet owners are rarely away from their pets, so an accurate reporting of pet-related symptoms may not be possible.

Skin tests or special allergy blood tests are helpful for diagnosing allergy to animals, but are not always accurate. To gain confirmation about a pet's significance as an allergen, the pet should be removed from the home for several weeks and a thorough cleaning done to remove the hair and dander. It should be understood that it can take weeks of meticulous cleaning to remove all the animal hair and dander before a change in the allergic patient is noted.

Are allergy shots effective for pet allergies?

Allergy shots (immunotherapy) may be indicated for cat or dog allergies, particularly when the animal cannot be avoided - as might be the case when the patient is a small animal veterinarian. They are typically given for at least three years and decrease symptoms of asthma and allergy. Usually after about six months of weekly injections allergy symptoms improve and less medication is required.

Allergy shots are most effective and safe when administered under the supervision of an allergist-immunologist. The response is highly individual and depends on environmental avoidance as well as the initial sensitivity of the individual.

What can I do when visiting people with pets if I am allergic?

The approach to visiting households with pets for an allergic individual is to take appropriate precautions including administration of medications prior to visitation. Your allergist-immunologist can provide information on medications for your animal allergy, such as antihistamines, nasal sprays, decongestants or appropriate asthma medications.

For patients who have severe symptoms on animal dander exposure, the pet should removed from the house at least day before the visit, and the host household should be cleansed of animal allergen to the extent practical.

So What It All Comes Down Too!

If you think you are allergic to "ANY ANIMAL" it is better to find out "BEFORE" you buy the pet!