There are two methods of specific allergy testing. One method is by skin testing
and the other method is by blood testing. The best type of testing is determined by your clinician at the time of your visit.
Skin Testing for Nasal Allergies
Skin testing is the most sensitive of the two methods as well as the most frequently used approach to evaluate allergic disease. There are two types of skin testing. One method is percutaneous or prick testing and the other method is intradermal testing. Allergy testing appointments are scheduled for one hour.
The consultation visit begins with a detailed discussion including a history of symptoms, exposures that affect symptoms, as well as details regarding home and work environments. These details determine the specifics of testing for each individual patient. Percutaneous or prick skin testing
is performed on the forearms or on the back. The skin is cleansed with alcohol and several testing stamp pads are pressed onto the skin surface. Each testing device is loaded with eight different allergens. Allergens are substances like pollens, dust mite, molds, and animal danders.
Most patients are screened for major representatives of each allergen group. Typically this involves about 24 tests or three stamp pad applications. Application of this test involves a mild “prick” sensation for a few seconds. The test results develop within fifteen to twenty minutes after application. Reactive positive control and any positive allergen will cause itching at the test site. This response is known as wheal and flare. This response is measured to reveal what an individual is allergic to and gives a degree of sensitivity. Additional testing by intraderamal method may be performed. Intradermal skin testing
involves individual needle sticks just below the skin surface. A small amount of testing antigen is injected beneath the upper skin surface to create a small wheal (bump). After fifteen to twenty minutes this area of response is measured. If the test is negative the wheal flattens and fades. If the test is positive the wheal increases in size and flares. This method of testing can detect mild sensitivities that might not be detected in prick testing. Intradermal testing is the most sensitive method of testing and is used to quantify test results and provide good starting doses for patients beginning allergy shots or immunotherapy.
Blood Testing for Nasal Allergies
Blood testing is available for allergy evaluation. This method can be used to evaluate small children or in patients who are on medications that prohibit skin testing. Blood testing can be used in patients with overactive skin that cannot be accurately skin tested. Blood is drawn and sent to lab for measurement of specific IgE antibody, which is the antibody that elevates in allergic individuals. The specific tests requested are determined by the patients specific history.
Details of skin testing are discussed with each patient on the day of testing. Treatment of allergic disease includes avoidance of offending allergen, use of medications and lastly, allergy injections or immunotherapy. An individual treatment plan is created for each patient following testing.
Preparation for Allergy Testing One week prior to testing it is important to stop all antihistamine medications
. This includes over the counter and prescription tablets, nasal sprays, as well as eye drops containing antihistamine. These medications will block the skin reaction that is measured to determine allergic responses.
Nasal decongestants, nasal steroid sprays, oral steroids or leukotriene medications such as Singulair do not affect skin testing and do no need to be stopped for allergy testing.
Antihistamines may be included in over the counter sleep aids or medications for vertigo. If you are uncertain, if you are taking an antihistamine check with your doctor’s office or pharmacist.
On the day of visit wear short sleeves or layers. Testing is typically performed on the arms. Bring a current and accurate list of medications including prescription and over the counter medications, vitamins and supplements. It is important for us to be aware of all medications that a patient is taking. Beta blocking medications and tryciclic antidepressants may affect skin test responses or change our approach to evaluating allergic status. Do not alter your use of these medications without specific instructions of the prescribing physician..
Wheal and flare reactions from skin testing peak at approximately 15 to 20 minutes after application. Skin test sites typically flatten and fade after one to two hours. Just like bug bites the less these sites are scratched the quicker the response fades. Application of a cool compress or topical antihistamine can be applied. In a rare patient skin test sites may be visible for 1 to 2 weeks. Positive reactions to mold are most likely to cause delayed skin responses appearing 1-2 days following testing.
The results of your allergy tests are discussed in detail on the day the tests are performed. You will receive detailed instructions regarding avoidance of allergens that may be producing symptoms. Your medication plan may be adjusted. An individualized treatment plan will be created.