Testing For Allergies
Allergy Tests
Allergy tests are simple, quick, and relatively painless. And
they're the best way to confirm whether or not a particular
allergen (or allergens) will cause a person to have an allergic
reaction. Typically a person will suspect that he or she is
allergic to something before taking an allergy test, so often an
allergy test is performed as a way to confirm a suspicion. Skin
tests and blood tests are the most common types of allergy tests
performed today.
Once the problem-causing allergen is singled out, that person
can then make the necessary modifications in his/her environment
and/or lifestyle to protect against an allergic outbreak. This
is important because allergic reactions can range from a simple
irritating skin outbreak all the way to serious difficulty with
breathing.
Skin Allergy Tests
In most situations, a skin test will be performed first as it
usually results in reliable findings. Plus, skin tests for
allergies are faster and less expensive than blood tests. With
skin tests, several allergens can be tested simultaneously. The
person administering the test begins by cleaning the test area,
either the back or the arm, with alcohol. Next, a liquid form of
the allergen is rubbed on the skin. If more than one allergen
will be included in the test, each will be spread 1 - 2 inches
apart. The location of each allergen likely will also be labeled.
Next either a needle (single prick) or an instrument with
between 5 to 10 pricks on it is used to break the surface of the
skin which causes the allergen solution to get into the skin. If
a reaction is going to occur, a raised, red, blotchy mark will
usually appear within 10 to 15 minutes. The medical term for
this appearance is a wheal and its appearance means that the
person has had a positive reaction to the allergen.
Sometimes if the test for an allergen is negative, another skin
test called an intradermal test is performed. This is where the
allergen is actually injected with a needle deep in the skin.
Again, if a wheal develops, that is considered a positive
reaction. A skin patch works off the same premise. A patch that
is soaked with an allergen is applied to the skin for about 2
days. The problem with the patch is that it will come off in the
water or sometimes from excessive sweat, so bathing and
exercising are advised against while the allergy tests are in
process.
Blood Allergy Tests
Blood tests require a sample of blood to be extracted from the
person's vein. The collected blood gets sent to a laboratory
where it is tested for the presence of allergen antibodies.
There is much debate as to whether or not one type of allergy
test is better than another. When in doubt, as with any
potential medical condition, it is always best to seek another
opinion or get another test. A decision about treatment should
be made only after discussing a person's test results and
history of symptoms with a trained medical professional.