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Tell me about Allergies!

Allergy Testing


There are several ways to test for allergies. The two most common are ways of diagnosing inhalant allergies- allergies to things you breath in like pollens, molds, danders, etc.  The two ways are blood testing and skin testing.  Skin testing is more accurate, so blood testing is used only for special situations.

There are some medications that interfere with the results of skin testing.  There are other medications that make skin testing less safe.  Both of these medication classes need to be stopped for 5-7 days before testing. 

While it is usually safe to stop your antihistamine allergy medication on your own, DON'T STOP ANY HEART, BLOOD PRESSURE, or EYE MEDICATION WITHOUT SPECIFIC APPROVAL FROM THE DOCTOR WHO PRESCRIBED IT!!!  

Here are allergy meds that are OK to take during the 5 days off antihistamines.

For blood testing, the physician decides what allergens to test you for, based on your history.  You have several small tubes of blood drawn in the lab.  The blood is then tested for IgE (the body's allergy messenger) against each of these substances.  The advantage of this is that it only takes a few minutes in the lab, and since no allergens are placed on the skin, there is absolutely no risk of a reaction.  This type of testing is particularly appropriate for people who's asthma is not well-controlled, who are pregnant, who have dermographism, who can't stop their antihistamine medication for 5 days before skin testing, or who are taking a high blood pressure medication or eye drop of the beta blocker class.

There are two methods of performing inhalant allergy skin testing

  • skin prick testing (SPT)
  • intradermal testing (IDT). 

For either of these, there are medications which can't be taken for 5-7 days before testing SPT tests in a very superficial level of skin.  We use the MultiTest II testing device, which has little plastic prongs which penetrate the superficial skin.  Children as young as 5 years old tolerate this type of testing.  For most patients, this gives us sufficient information.  Occasionally, if these test results are ambiguous, we will proceed with intradermal testing. This places antigen at a slightly deeper layer of the skin. It forms a little bleb, similar to a TB skin test. 

 

For situations where we suspect that something contacting your skin is causing allergic problems, we perform patch testing.

If we find out that it doesn't look like allergies are causing your problem, we take our treatment in one direction.  If you DO have allergies, this useful information helps us craft your individualized treatment.