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Q. WHAT
DISEASES OR CONDITIONS ARE TREATED WITH ALLERGY SHOTS?
A. "Allergy Shots" (the
medical term is allergen immunotherapy) are used to treat some cases
of respiratory allergic diseases. This means those allergic diseases
affecting the nose, lining membranes of the eye, and bronchial
tubes. The medical name for allergy affecting the nose is allergic
rhinitis; allergens in the air affecting the membranes lining
the eyeball is termed allergic conjunctivitis; allergic reactions
to airborne substances which occur in the bronchial tubes in the
lungs may cause inflammation and spasm of the lining of the bronchial
tubes, which is known as asthma. Allergy shots are also used to
prevent future reactions in persons who have had serious allergic
reactions to venoms of stinging insects.
Q. DOES
EVERY PERSON WHO HAS PERSISTENT NASAL PROBLEMS OR ASTHMA
NEED ALLERGY SHOTS?
A. NO. Many
cases of persistent nasal symptoms or asthma are not caused by
allergy to airborne substances and will not respond to treatment
with allergy injections. Many cases which are indeed caused by
allergy can be satisfactorily treated by allergen avoidance or
medication, without need for allergy injections. Whether
allergen injection treatment is indicated is determined by evaluation
of the individual patient's case by an allergy and clinical immunology
specialist.
Q. WHAT DO ALLERGY
SHOTS CONSIST OF?
A. Allergy shots consist of the unavoidable
ariborne allergens to which the particular patient has been found
sensitive in a purified and sterilized form.
Q. HOW DOES INJECTING
THE ALLERGENS INTO A PATIENT HELP IN CONTROLLING THE ALLERGIC DISEASE?
A. Injecting
these substances stimulates the body's protective mechanisms to
produce immunity to the allergens, which partially counteracts
the effects of the allergic antibodies in the patient's body which
promote allergic reactions on exposure to the allergens. The process
of acquiring partial immunity to allergen exposure has some similarity
to that involved in vaccination with viruses and bacteria, such
as polio and tetanus.
Q. DOES IT MATTER
HOW MUCH ALLERGEN IS GIVEN IN THE INJECTIONS?
A. Yes. It is
absolutely crucial that an adequate dosage of each allergen be
given in order for treatment with allergy shots to be effective.
If the dosage used is too low, the immune system will not be adequately
stimulated to produce protective antibody.
Q. WHY DO ALLERGENS
NEED TO BE GIVEN BY INJECTION?
A. It is not
possible with materials currently routinely
available in the United States for an effective amount of allergens to be absorbed into
the body by any other route.
Q. HOW SOON DO ALLERGY
SHOTS TAKE EFFECT?
A. Usually
it takes several months for allergy shots to produce a noticeable
effect. The reason that it takes so long is that the
initial dosage must be very low, too low to stimulate the immune
response. In the first few months of injection treatment, each
dose is greater than the one before. Protection against the effects
of allergen exposure occurs only after the higher dosages are reached.
If the dosage were to be started too high or increased too rapidly,
unpleasant reactions may occur. The principle behind allergy immunizations
is that immunity is build-up in a stepwise manner, so that the
protective response produced by the first injection permits a higher
dose to be given on the second injection, and so forth, until the
full dose is finally reached. Usually the final, protective dosage
is 1000 to 10,000 times higher than the starting dosage. Often
patients continue to have gradual improvement in their allergy
symptoms over the first two years of injection treatment. In general,
whatever degree of improvement that can be expected from allergen
immunotherapy will have occurred by three years after initiation
of therapy.
Q. SINCE IT TAKES
SEVERAL MONTHS FOR ALLERGY SHOTS TO BEGIN TO WORK, DOES THE PATIENT
SIMPLY HAVE TO SUFFER IN THE MEANTIME?
A. No. Sixty years ago
this was true, but now there are many effective medications (pills and sprays)
available for treatment of inhalant allergy. Most of these take effect within
hours to days. When allergy shots do begin to take effect, the amount
of pill or spray medication needed to control the condition is decreased.
Because of the long interval between beginning allergen injection therapy and
the onset of benefit, allergy shots are used as an adjunct to treatment with
oral medication and nasal sprays or bronchial inhalers, which take effect much
more rapidly.
Q. WILL ALLERGY SHOTS
COMPLETELY CURE NASAL ALLERY OR ASTHMA?
A. No. Symptoms
of inhalant allergy are lessened and requirement of allergy medications
is greatly decreased in most cases, but the vast majority of patients
continue to have some allergy symptoms and need some oral or spray
medications despite receiving allergy injections. Complete remission
of allergy symptoms occurs only in a very small number of patients.
Q. WHAT ARE THE
SIDE EFFECTS OF ALLERGY SHOTS?
A. The most common side effect of allergy
injections is mild soreness, redness, swelling, local heat and
tenderness at the site of the injections. Typically this is greatest
2 or 3 hours after the injection and is gone by the next morning.
If such local reaction lasts over 24 hours, the dosage should be
held steady and not increased until the excessive degree of local
reaction is no longer occurring. Nearly all patients receiving
allergy injections have some local reaction - it is a sign that
the body is making immunity, the local reactions usually become
less of a problem, and the dosage can continue to be increased.
A potentially much more serious effect of allergy injections is
a systemic reaction. Only a small minority of patients have this
type of reaction.
Q. CAN
SYSTEMIC REACTIONS BE DANGEROUS?
A. Yes. Signs and symptoms of systemic
reactions include breaking out in welts all over the body, sneezing
or coughing attack, wheezing, flushing, racing heart, weakness,
fall in blood pressure, fainting and swelling of the face, tongue,
and throat. Typically such reactions begin within one-half hour
of the injection, but occasionally they may not occur until 2 hours
after the injection. In extremely rare cases, systemic reactions
to allergy injections can be fatal, due to interference with breathing
and fall in blood pressure.
Q. WHAT
IS DONE TO TREAT A SYSTEMIC REACTION IF IT OCCURS?
A. Systemic reactions are treated with
an injection of epinephrine (adrenaline) under the skin, which
usually acts promptly to stop the reaction. Severe reactions may
require more intensive treatment in addition to the epinephrine.
Q. IS
THERE ANYWAY OF COMPLETELY PREVENTING SYSTEMIC REACTIONS?
A. No. The administration of effective dosages of
allergy extracts entails a small but unavoidable risk of systemic reaction. The
incidence and severity of systemic reactions is diminished, however, by meticulous
attention to detail in all aspects of the treatment.
Q. IF A SYSTEMIC REACTION OCCURS,
SHOULD ALLERGY INJECTIONS BE STOPPED?
A. No. In general, patients who have systemic reactions
have large amounts of allergic antibody in their body, and stand to benefit the
most from allergy injection treatment. If a systemic reaction occurs, the dosage
needs to be temporarily reduced and then built up slowly again.
Q. HOW OFTEN ARE ALLERGY INJECTIONS
GIVEN?
A. Since benefit from allergy injections requires
that a relatively large dosage be attained, injections are given frequently at
the beginning of treatment, usually once or twice weekly. Once the maintenance
dosage (full dosage) is reached, the injections are spread out to every two weeks,
and eventually to once a month.
Q. WHY MUST ALLERGY INJECTIONS
BE GIVEN REGULARLY ?
A. Injections must be given regularly for reasons
of safety and effectiveness. Systemic reactions are more frequent when injections
are given erratically; the escalations in dosage required to build effective
immunity cannot be made if an excessive period of time has elapsed between injections.
Q. SHOULD PATIENTS HAVE ALLERGY
INJECTIONS MORE FREQUENTLY WHEN THEY ARE HAVING MORE SYMPTOMS ?
A. No. While this was a popular practice several
years ago, more recent research has clarified that allergy injections act as
a prophylactic treatment - if taken regularly prior to exposure
to allergens, patients have less intense symptoms when they are exposed to the
allergens. There are now a variety of effective medications for treatment of
allergy symptoms when
they occur.
Q. HOW LONG DOES A PATIENT
CONTINUE TO TAKE ALLERGY INJECTIONS ?
A. Several years of treatment are required to attain
lasting improvement, which persists long-term after injections are stopped, in
the patient's allergic condition. The duration of treatment is determined for
each patient on an individualized basis. If injections are given for less than
three years, relapse is expected.
Q. SHOULD PATIENTS GIVE THEIR
OWN INJECTIONS ?
A. Allergy injections should be NEVER be
self-administered by the patient. The primary reason for admonition is that in
the event of a systemic reaction, the patient may rapidly become too ill to self-administer
epinephrine rapidly and take other necessary emergency measures. Injections are
best administered in clinics where physicians and nursing staff are very familiar
and experienced with allergen treatment. Epinephrine must be immediately available
when allergy injections are given.
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