Who Gets Pet
Allergies?
Six out of 10 people in
the United States come in contact with cats or dogs. The total
pet population is more than 100 million, or about four pets
for every 10 people.
Allergies to pets with fur
or feathers are common, especially among people who have other
allergies or asthma. From 15 percent to 30 percent of people
with allergies have allergic reactions to cats and
dogs.
People with dog allergies
may be allergic to all dogs or to only some breeds. Cat
allergies are about twice as common as dog
allergies.
What Causes a Pet
Allergy?
The job of immune system
cells is to find foreign substances such as viruses and
bacteria and get rid of them. Normally, this response protects
us from dangerous diseases. People with pet allergies have
supersensitive immune systems that react to harmless proteins
in the pet's dander (dead skin that is shed), saliva or urine.
These proteins are called allergens.
Dogs and cats secrete
fluids and shed dander that contain the allergens. They
collect on fur and other surfaces. The allergens will not lose
their strength for a long time, sometimes for several months.
They appear to be sticky and adhere to walls, clothing and
other surfaces.
Pet hair is not an
allergen. It can collect dander, though. It also harbors other
allergens like dust and pollen.
Cat and dog allergens are
everywhere. Pet dander is even in homes never occupied by
these animals because it is carried on people's clothing. The
allergens get in the air with petting, grooming or stirring
the air where the allergens have settled. Once airborne, the
particles can stay suspended in the air for long periods of
time.
What Are the
Symptoms?
Reactions to cat and dog
allergens that land on the membranes that line eyes and nose
include swelling and itching of the membranes, stuffy nose and
inflamed eyes. A pet scratch or lick can cause the skin area
to become red.
If allergen levels are low
or sensitivity is minor, symptoms may not appear until after
several days of contact with the pet.
Many airborne particles
are small enough to get into the lungs. When inhaled, the
allergens combine with antibodies. This can cause severe
breathing problems—coughing, wheezing and shortness of
breath—in highly sensitive people within 15 to 30 minutes.
Sometimes highly sensitive people also get an intense rash on
the face, neck and upper chest.
For about 20 percent to 30
percent of people with asthma, cat contact can trigger a
severe asthma attack. Cat allergies also can lead to chronic
asthma.
How Is a Pet Allergy
Diagnosed?
If a pet allergy is
suspected, the doctor may diagnose it by taking a medical
history and testing the blood of the patient. Some people are
so attached to their pets that they will deny the pets could
cause their symptoms. In these cases, the patient is removed
from the animal's environment to see if symptoms go away. It
does not help to remove the dog or cat. Allergens still in the
area can cause symptoms months after the animal is
gone.
To diagnose cat-induced
asthma, the patient must have both of the
following:
-
Asthma symptoms when
exposed to cat or cat allergen
-
An allergic reaction to
a skin test or to a blood test called RAST
(radioallergosorbent test). To make sure the diagnosis is
correct, the doctor will watch what happens when a cat is
added then removed from the patient's environment several
times.
What Is the Best
Treatment?
The best treatment is to
avoid contact with cats or dogs or their dander. Keep the pets
out of the house, and avoid visiting people with pets.
Avoiding cats and dogs may give you enough relief that you
will not need medication.
Keeping the pet outdoors
will help, but will not rid the house of pet allergens.
Another option is to have pets that do not have fur or
feathers. Fish, snakes or turtles are some choices.
What If I Want to Keep
My Pet?
To test the effect of
household pets on your quality of life, remove them from your
home for at least two months and clean thoroughly every week.
After two months, if you still want pets, bring a pet into the
house. Measure the change in your symptoms, then decide if the
change in your symptoms is worth keeping the pet.
If you decide to keep a
pet, bar it from the bedroom. You spend from one-third to
one-half of your time there. Keep the bedroom door closed and
clean the bedroom aggressively:
-
Because animal allergens
are sticky, you must remove the animal's favorite furniture,
remove wall-to-wall carpet and scrub the walls and woodwork.
Keep surfaces throughout the home clean and uncluttered.
Bare floors and walls are best.
-
If you must have carpet,
select ones with a low pile and steam clean them frequently.
Better yet, use throw rugs that can be washed in hot
water.
-
Wear a dust mask to
vacuum. Vacuum cleaners stir up allergens that have settled
on carpet and make allergies worse. Use a vacuum with a HEPA
(high efficiency particulate air) filter if
possible.
-
Forced-air heating and
air-conditioning can spread allergens through the house.
Cover bedroom vents with dense filtering material like
cheesecloth.
-
Adding an air cleaner
with a HEPA filter to central heating and air conditioning
can help remove pet allergens from the air. The air cleaner
should be used at least four hours per day. Another type of
air cleaner that has an electrostatic filter will remove
particles the size of animal allergens from the air. No air
cleaner or filter will remove allergens stuck to surfaces,
though.
-
Washing the pet every
week may reduce airborne allergens, but is of questionable
value in reducing a person's symptoms.
-
Have someone without a
pet allergy brush the pet outside to remove dander as well
as clean the litter box or
cage.
