Aspirin is a natural compound
Aspirin is a useful medication, used to reduce pain and inflammation.
Originally derived from plants extracts, these days, aspirin is
made synthetically. A number of similar synthetic non-steroidal
anti-inflammatory drugs (NSAIDS) with similar properties are also
available.
Aspirin allergy may occur
Mild to severe allergic reactions to
aspirin may occur. Symptoms include flushing, itchy rashes,
blocked and runny noses and severe difficulty breathing or asthma,
usually within an hour of taking a tablet.
Testing for aspirin allergy is difficult
Why allergic reactions to aspirin and related pain-killers
occur is uncertain. There is no reliable blood or skin allergy
test which has been proven to be useful for confirming or excluding
sensitivity to these medicines. The only way to do so is to do
a graded open challenge under strict medical supervision. Challenge
testing is not always necessary, but may sometimes be advised
to prove that sensitivity exists, or to prove the safety of an
unrelated medicine.
Samter's triad / Aspirin triad
Some patients suffer from aspirin allergy,
nasal polyps and asthma, a condition
known as the aspirin triad. Aspirin allergy can develop later
in life, even when previously well tolerated. Often asthma is
of later onset as well, and sufferers may not be allergic to inhaled
allergen like dust mite, animals, moulds or pollens. Patients
with this condition produce increased quantities of leucotrienes.
Leucotrienes are inflammatory chemicals produced by white cells
that increase inflammation in the nose, sinuses and lungs and
can trigger runny noses and wheezing. The result is worse asthma
and accelerated polyp growth.
Patients may benefit from aspirin desensitisation
Even though these patients are allergic to aspirin, most can
be made to tolerate high doses by starting off at a very low dose
of aspirin initially and increasing it day by day. Once a higher
dose is reached (generally 1 4 tablets/day), there is reduced
production of leucotrienes. Aspirin desensitisation has been shown
to reduce asthma severity, the rate of polyp growth, the number
of sinus operations needed and the severity of sinusitis. Sometimes,
you may need to do a deliberate aspirin challenge to find out
whether you are allergic to aspirin or not. The decision to undertake
aspirin desensitisation is best made by an allergy specialist.
Other medicines may also be helpful
There are also asthma medications known as anti-leucotrienes
(eg. Singulair, Accolate) that can also be used in this situation.
Unfortunately, they are currently very expensive.
Side-effects of aspirin desensitisation
Reasons for undertaking aspirin desensitisation in aspirin sensitive patients
Dietary salicylates are only occasional triggers in aspirin-sensitive
patients
Occasional patients who are allergic to aspirin, and have
the "aspirin triad", will suffer symptoms if they eat
foods that have high levels of natural salicylates. This affects
the occasional patient rather than the majority, and low salicylate
diets are not considered a routine part of management.
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