IT'S SPRING AGAIN AND ALLERGIES ARE IN BLOOM 
by Ken Flieger

Chances are that you would just as soon not think about your nose.  As long 
as it lets air in and out fairly easily, sniffs a nice aroma now and then,
and keeps eyeglasses in place, a nose is, well, forgettable.

But for 25 million to 30 million Americans who suffer from seasonal allergic
rhinitis--better (if inaccurately) known as hay fever--it is sometimes hard 
to think of anything but their noses.  When a hay fever victim's particular 
nemesis is in the air, he or she is apt to be preoccupied by a constant 
struggle against the ailment's classic symptoms--watery nasal discharge,
runny eyes, violent fits of sneezing, and itching that can affect not just
the nose, but the roof of the mouth and even the Eustachian tubes connecting
the inner ear to the back of the throat.

If tree pollen is the culprit, this all-out barrage against the nose and its
neighbors usually strikes in early spring.  Grass pollen tends to be
troublesome in late spring and summer, and the deservedly notorious ragweed 
pollen is most abundant in the fall.  Depending on where they live, hay fever 
victims who react to all three types of pollen may get a respite only in
mid-summer and the dead of winter.

On the other hand, a hay fever sufferer who is allergic to molds, house dust, 
or animals may have to contend with symptoms the year 'round.  So do people 
whose attacks are triggered by industrial pollutants, cigarette smoke, and
other airborne irritants and allergens where they live or work.  These
unfortunate souls have "perennial allergic rhinitis." Their hay fever never 
lets up.

If that is the bad news, the good news is that a lot can be done to help hay
fever sufferers cope with the disease.  Better understanding of the complex 
events involved in an allergic reaction has made possible substantial 
improvement in the care of allergy patients, whether they have hay fever, 
asthma, food allergies, or any of a wide range of distressing and sometimes 
life-threatening allergic diseases.  Medical science cannot cure allergies
the way it can pneumonia.  But advances in treatment and prevention allow 
millions of people to avoid the torment that can plague anyone unfortunate
enough to "have allergies." 

Allergies or a Cold 

Allergists (physicians who specialize in treating allergies) think that a 
good deal of allergic disease is unrecognized and therefore untreated.  One 
reason is that seasonal allergies can easily be mistaken for a cold.  Careful 
observation and common sense are useful guides to whether a stuffy, runny 
nose and sneezing signal a cold or an allergy.  If the symptoms last more 
than a week or so, if they go on virtually all of the time, if they start and 
stop at the same time every year, flare up around cats or horses (principal 
causes of animal allergy), or otherwise follow a consistent pattern, allergy
ought to be suspected.  To be more certain, however, appropriate tests should 
be done by a physician, preferably an allergist.

The diagnosis of allergic rhinitis--the medical term for the inflamed, runny
nose that's the main symptom of  "allergies"--is based on a detailed patient
history and examination of the nose.  But the most critical step is skin
testing.  Tiny, diluted amounts of suspected allergens are injected under the 
skin or applied to a small scratch or puncture on the patient's arm or back.
Within about 15 minutes, if the patient has IgE antibodies (see accompanying
article) to an allergen being tested, a small raised area surrounded by 
redness--the "wheal and flare" reaction--will appear at the test site.  The 
size of the skin reaction indicates how sensitive the patient is to the 
allergen that caused it.

Paul C.  Turkeltaub, M.D., of FDA's Center for Biologics Evaluation and 
Research, and researchers at the National Center for Health Statistics
examined information on allergen skin testing collected between 1976 and 1980 
in the Second National Health and Nutrition Examination Survey.  Among more 
than 16,000 people aged 6 to 74, about one in five had skin reactions to at 
least one allergen.  Ryegrass and ragweed pollen each produced reactions in 
over 10 percent of the people tested, 6.2 percent were sensitive to house 
dust, and 2.3 percent showed a reaction to cats.  More than twice as many 
people reacted to allergens found outdoors than to those found indoors. 

Not everyone who tests positive for specific IgE antibodies necessarily has 
allergy symptoms.  Nevertheless, many allergists think that allergic disease
of one kind or another--hay fever, asthma, drug allergy, or an allergic 
reaction to certain foods or insect stings--is likely to appear sooner or 
later in a person who has no symptoms but who has a positive skin test. 
About 80 percent of people who develop allergic rhinitis do so before the age 
of 30.  But the disease has also first appeared in people in their 70s or 80s.

Shots and Other Relief

Before the 1940s brought the general availability of antihistamines, hay
fever sufferers could get little help from the pharmacy.  A hundred and fifty 
years ago, the English clergyman, wit, and hay fever victim Sydney Smith--he
said his sneezes could be heard for six miles--put opium in his nostrils to 
relieve "this little upstart disease." Today allergic rhinitis can be 
controlled by more effective and much less dangerous drugs. 

Antihistamines, available both over the counter and by prescription, remain 
the most widely used agents to treat hay fever symptoms.  They can be highly
effective in controlling itching and sneezing, but do less well in clearing 
nasal congestion.  Antihistamines are most effective when used regularly
rather than sporadically.  Their chief undesirable side effects are 
drowsiness and excessive drying of tissues.  Newer antihistamines, such as
the prescription medication Seldane (terfenadine), are less apt to cause
these side effects. 

Nonprescription decongestants that shrink blood vessels in and around the 
nasal passages may help relieve nasal stuffiness.  Decongestants are often
sold in combination with antihistamines in the form of tablets, capsules, 
caplets and liquids.  Others are sold as nose drops or sprays.  While very
effective for short-term use--a few days at most--overuse of nose drops and 
sprays can cause a "rebound" effect in which the congestion comes roaring 
back worse than ever.  Patients can get caught in a vicious circle of use,
relapse, and more use.  The only solution is to stop using the drug 
altogether. 

Intal or Nasalcrom inhalers (active ingredient cromolyn sodium), available by 
prescription, were first used against asthma and are proving useful in
treating hay fever as well.  For most people, inhaled cromolyn has few if any 
side effects, but must be taken frequently--every four hours--to be of
maximum benefit.  The corticosteroids, hormone-like drugs that suppress the 
immune response, may also be useful in relieving allergy symptoms.  They are
usually administered as sprays, but are sometimes taken by mouth.  While
long-term use of oral corticosteroids can depress the activity of the adrenal 
glands, resulting in diminished resistance to infection, and cause other
serious side effects, the nasal preparations used to treat allergic rhinitis
are not thought to have any effect on the body as a whole.  Corticosteroids 
are available only by prescription. 

Allergen immunotherapy--"allergy shots"--offers another effective approach to 
controlling hay fever symptoms.  First employed in the 1920s, immunotherapy 
consists of injecting gradually larger amounts of the allergens that cause
the patient's allergic response.  At the beginning of the  treatment the dose 
is intentionally much too small to cause a reaction.  The dose is gradually 
increased to a level that protects the patient from whatever is causing the 
allergy.  It usually takes six to 12 months to reach a protective dose.  Once 
protection has been achieved, patients are given  maintenance shots at four-
to six-week intervals to keep symptoms under control.  Whether or not the 
patients can successfully stop receiving allergy shots is uncertain.  Studies 
suggest that protection fades if the shots are discontinued.  For that
reason, some allergy specialists recommend that they be continued 
indefinitely. 

Aiming for Improvements 

FDA is actively seeking to standardize the commercially available extracts
used in skin testing and immunotherapy to improve their safety and
effectiveness.  The agency has two main objectives: expanding the 
availability of  single-allergen extracts (individual kinds of pollen, for
example, rather than extracts containing mixtures of several allergenic 
pollens); and standardizing extracts on the basis of how strong a skin
reaction they produce.  Studies have shown, for example, that weed and grass
pollen extracts are more than 10,000 times as potent in producing skin
reactions as extracts made from white pine and mountain cedar pollen.  The
labeling of standardized extracts reflects such  differences in terms of
"allergy units." Using  single-allergen, standardized extracts, physicians
are better able to tell precisely what causes a patient's symptoms and to 
plan, if necessary, the most effective course of allergy shots. 

Immunotherapy has proven effective in hay fever sufferers and can be little 
short of miraculous for some patients who cannot get adequate relief either 
from avoiding allergens or from medication.  Allergy shots are, however,
time-consuming and costly and entail a slight risk of causing the kind of 
reaction they are meant to prevent.  Because such a reaction can be serious,
doctors like to monitor patients for at least 20 minutes after giving the 
shot. 

The best course of action in treating hay fever is to get a careful diagnosis 
and discuss treatment options with an allergist.  Once a hay fever sufferer's 
problem has been diagnosed, a doctor often can show how symptoms can be 
controlled by avoidance of the allergen or allergens involved or by the 
careful use of over-the-counter antihistamines and decongestants.  If 
prescription drugs or immunotherapy are called for, a physician can recommend 
the most appropriate course of treatment.  The important thing is that
virtually every hay fever sufferer can be helped by prevention and treatment. 

Noses are remarkable.  They filter the air we breathe, warm it when it's too
cold, and moisten it when it's too dry.  They alert us when food might be 
unsafe to eat, and some noses can even smell a rain storm coming.  Yet, with
the possible exception of Bob Hope, we would all be grateful if noses went
about their impressive variety of tasks unnoticed.  For hay fever victims,
that would be a blessing.  Thanks to medical science, it's a blessing 
millions of them can enjoy.  ? Ken Flieger is a free-lance writer in
Washington, D.C.
                                   
                        AN OVERACHIEVER IMMUNE SYSTEM 

Seasonal allergic rhinitis--hay fever--is the most common allergic disease. 
Its medical name means inflammation of the membrane lining the nose caused by 
exposure to an allergen at specific times of the year.  (Hay is almost never
its cause, and fever is not one of its symptoms, but the misnomer has stuck 
since it was coined more than 160 years ago.) Research, most of it in the 
20th century, has demonstrated that allergy is actually an altered or 
exaggerated immune response.  In an allergy-prone person the immune system
reacts powerfully to foreign substances, such as pollen, that simply do not 
bother most of us.

The phenomenon of immunity has long been recognized.  Ancient scribes 
reported that survivors of plague seemed to be protected if the disease 
struck again.  Fifteenth century Chinese and Arab physicians tried injecting
people with pus taken from smallpox victims.  Sometimes the result was a mild 
case of smallpox that protected against the more serious form of the
disease.  Sometimes, too, the outcome was severe smallpox and death.

Two centuries ago, an English physician named Edward Jenner successfully
immunized a young boy against smallpox by injecting him with a fluid from a 
cowpox sore--hence the term vaccination--from vacca, Latin for cow.  But it 
was not until the late 19th and early 20th centuries that scientists began to 
explore the immune system and discover that it is responsible for a number of 
illnesses, including allergies. 

The mechanisms by which the human body recognizes its own components and
distinguishes them from foreign substances are among the most elegant 
products of evolution.  (See "The Immune System: Your Body's Department of
Defense," FDA Consumer, March 1988.) Although they do not understand it 
fully, scientists believe the immune system consists of two main branches.
One works through the action of white blood cells called T lymphocytes, or
simply T cells.  T cells attack foreign materials directly and also produce 
substances that summon other parts of the immune system to help destroy an
invader.  A deficit of T cell-mediated immunity is characteristic of acquired 
immune deficiency syndrome. 

The other branch of the immune system is the one we associate with
antibodies--highly specialized proteins manufactured by B lymphocytes--and
antigens--enzymes, toxins, or other foreign substances that provoke a 
response from the body.  When B cells encounter antigens, such as those on
the surface of bacteria, they multiply and produce antibodies that destroy
the invading germ or make it vulnerable to attack by other parts of the 
immune system.  Once B cells have learned to make an antibody against a 
specific antigen, they go on making it indefinitely.  This is why vaccines
can induce permanent immunity against some diseases.

Ironically, it is the immune system's ability to maintain constant readiness
against a repeat onslaught by an antigen that makes millions of people
susceptible to allergic disease.  For reasons that are not entirely clear,
some antigens cause B cells to make a kind of antibody called immunoglobulin
E--IgE for short.  (Antigens that provoke IgE formation are referred to as
allergens because they can cause an allergic reaction.) The first time an 
allergy-prone person is exposed to an allergen--pollen or house dust for
example--the B cells respond by making IgE antibodies tailored to counteract
the allergen.  These IgE antibodies attach themselves to mast cells that are
abundant in the respiratory tract, digestive system, and skin and to
basophils, cells circulating in the blood.

The next time an allergen and its IgE antibodies come together, mast cells
and basophils release powerful substances called mediators, among them
histamine, that cause the allergic reaction.  These mediators are fairly
rapidly neutralized by the body.  But as long as the allergen is present, 
histamine and other mediators will continue to be released from mast cells
and basophils, and the patient's allergy symptoms will persist. 

No one knows for sure why some people have allergies while most do not. 
Genetics appears to play a part; people who suffer from allergies usually 
have a close relative with similar problems.  Susceptibility seems to be
related to a person's capacity to produce IgE antibodies.  Yet only 30
percent to 40 percent of people with allergic rhinitis have high IgE levels,
and individuals with low IgE levels can still suffer from hay fever and other 
allergies.

In view of all the grief they cause, you have to wonder if IgE antibodies are 
good for anything.  The answer may well be yes.  Studies suggest that several 
kinds of human parasites provoke the formation of IgE antibodies and are
rapidly destroyed by them.  (These amoebas and worms are no longer common in
this country, but they still cause serious health problems in underdeveloped
parts of the world.) Looking at this intriguing discovery, a Swedish
immunologist has  speculated that "pollen allergy might partly be an
undesirable consequence" of modern society's success in ridding itself of 
parasites and the diseases they cause.
                                   

                      ABSENCE MAKES THE NOSE GROW FONDER

Once hay fever has been diagnosed and the responsible allergen or allergens 
identified, the first line of defense is prevention--avoiding the pollen, 
house dust, mold spores, scales shed by the skins of animals (dander), or 
other substances that provoke an allergic reaction. 

Sometimes this can be fairly easy.  A patient may hate to part with a pet cat 
or give up horseback riding, but that may be all it takes to be free of 
symptoms.  People allergic to mold spores may solve their problem by keeping
out of damp, musty areas.  They may also be well advised to avoid foods such
as peanuts that may contain mold spores and not to take penicillin and
similar drugs that can cause an allergic reaction in mold-sensitive people. 

If house dust is the problem, frequent and thorough cleaning of the floors, 
fabrics such as carpets and curtains, upholstered furniture, and bedding can
be beneficial.  So can the use of high-efficiency indoor air-filtering
devices (not those built into ordinary heating and air conditioning systems)
that trap dust particles.  (Filtering devices that really help don't come 
cheap.  Beware of inexpensive--and ineffective--substitutes.) Persuasive
evidence points to microscopic mites as the prime offenders in house dust 
allergies.  While these spider-like creatures thrive during warm summer 
months, they may actually be more troublesome in colder weather when
fragments of dead mites are more readily dispersed in the air and inhaled.

It is more difficult to avoid pollen and other outdoor airborne allergens.
Air conditioning helps in homes,  automobiles and workplaces.  Simply keeping 
doors and windows closed can lower the allergen content of indoor air.  Hay 
fever symptoms can be brought on by pollen concentrations as low as 20 grains 
per cubic meter of air; so during certain seasons, no outdoor area can be 
assumed pollen-free.  Yet it is wise to be especially wary of areas known to
have high concentrations of allergens.  Another prudent measure for allergic
rhinitis sufferers is to avoid irritants such as tobacco smoke, fumes,
polluted air, and hair sprays.

It is seldom helpful to move someplace else to escape hay fever-causing 
pollen.  Every part of the country has varieties of trees, weeds and grasses
that shed allergenic pollen.  People who try moving to the West Coast to
escape ragweed pollen (ragweed does not grow in California, Oregon or 
Washington) may discover that they are allergic to a pollen found in the new
location.  Furthermore, pollen grains have been found in air samples
collected as far as 400 miles at sea.  The adage "you can run but you can't 
hide" is all too true for most hay fever sufferers.