One of the many techniques a qualified Allergist use to diagnose allergy is the skin prick test. Properly performed, it is the most accurate method to diagnose allergic sensitization and better than any simply ordered blood test panel.
Skin prick test involves direct testing of the allergen on the person suspected of allergy (in-vivo) thus the results are individualized to the person being evaluated. As a result, skin prick testing is the gold standard in which other indirect testing are compared to.
The skin prick test is a painless procedure and results from the skin prick test can be interpreted within 15 minutes. As a result, the Allergist can have immediate interaction with the patient for proper clinical correlation.
When scheduled for a skin prick test, please avoid antihistamines as these medications can interfere with the result of the skin test.
Medications that can interfere with skin prick testing
No prescription or over the counter antihistamines should be used 5 to 7 days prior to scheduled skin testing. These include cold tablets, sinus tablets, hay fever medications, or oral treatments for itchy skin. Some allergy eye medications have antihistaminic activity and will need to be discontinued prior to testing. Examples include but not limited to (Aerius, Atarax, Claritin, Clarinase, Panadol Cold Flu, Pataday, Polaraimine, Piriton, Promethazine, Telfast, Xyzal, Zyrtec)
Other prescribed drugs, such as amitriptyline hydrochloride (Elavil), doxepin (Sinequan), and imipramine (Tofranil) have extended antihistaminic activity and should be discontinued at least 2 weeks prior to receiving skin test.
Asthma inhalers (inhaled steroids and bronchodilators), leukotriene antagonists (e.g. Singulair, Accolate) and oral theophylline (Theo-Dur,T-Phyl, Uniphyl, Theo-24, etc.) DO NOT interfere with skin testing and should be used as prescribed.