Skin tests are a method of testing for allergic antibodies. A small amount of the allergen is introduced onto the skin. Results are read 15 to 20 minutes after the application of the test. A positive reaction consists of a wheal (hive or whelp) in the area at the test site. The skin test methods used are:
- PUDDLE METHOD:
A small amount of allergen or suspected substance is placed on the skin (in a puddle form) and results are read 15-20 minutes after application. A positive reaction consists of erythema and/or wheal (redness or hives).
- DERMAPICK METHOD:
A sterile plastic device with several small points covered with test material is gently pressed into the skin on the back and rotated. This causes a superficial disruption of the upper surface of the skin. There is no bleeding and the discomfort is minimal.
- INTERDERMAL METHOD:
This method consists of injection a small amount of the allergen into the superficial layers of the skin. Several of these tests may need to be done on the upper arm area after Dermapick screening.
- PATCH METHOD:
Method for contact skin reactions. This can be a standard or custom designed test for items that you contact (i.e., chemicals, make-up, detergent, soaps, hair products, and lotion). Test items are placed on your back and are checked each day for 4 straight days.
Interpreting the clinical significance of the skin tests requires skillful correlation of the test results with patient's allergic history. Positive tests indicate the presence of allergenic antibodies and are not necessarily correlated with severity of clinical symptoms. After allergy shots some people continue to have allergy test reactions even with excellent reduction in symptoms.
You will be skin tested to airborne allergens and possibly some foods. Airborne allergens include trees, grasses, weeds, molds, dust mites, and animal dander. Testing generally takes between 2 to 4 hours.
Positive reactions will gradually disappear over 30 - 60 minutes, and typically, no treatment is required for the positive reactions. Occasionally delayed swelling at a test site will occur 4 to 8 hours after skin testing. These reactions are not serious and will disappear over the next week or so. They should be measured and reported to the doctor at your next visit.
You may be scheduled for skin testing to certain antibiotics, local anesthetics ("caines"), insect venoms, or other biological agents. The same guidelines apply as for inhalant and food testing.
Skin testing will be administered under Dr. Smith's direct guidance; occasionally reactions may require medical intervention. Very strong responses require the remainder of the test to be administered at another visit. These reactions may consist of any or all of the following symptoms: itchy eyes, nose, throat, nasal congestion, runny nose, tightness in the throat or chest, wheezing, light-headedness, hives, and/or generalized itching. SEVERE REACTIONS RARELY OCCUR AND THE STAFF IS FULL TRAINED AND MEDICALLY EQUIPPED TO HANDLE ALLERGIC EMERGENCIES.
- DO NOT use prescription or over-the-counter antihistamines 5 to 7 days prior to skin testing. These include cold tablets, sinus tablets, hay fever medications or oral medications for itchy skin (i.e. Atarax (hydroxyzine), Benadryl, Actifed, Drixoral, Dimetapp, Dristan, Tavist, Trinalin, Triaminic, Claritin, Allegra, Zyrtec, and Chlor-Trimeton).
- DO NOT stop taking the following medications which have an antihistamine effect without first checking with the doctor who prescribed them. Tagament and Zantac, amitrityline (Elavil), doxepin (Sinequan), imiprimine (Tofranil).
- DO NOT stop taking a "beta-blocker" medications used for high blood pressure, headaches, or glaucoma without first checking with the doctor who prescribed the medication. if you are being treated for hives, please call our office. Your first office visit may be a consult without skin testing if your hives are not under control at that time.
Should you have any questions regarding medications and skin testing, please call our office. Your Pharmacist can advise you if the medications you are taking are Beta Blockers or antihistamines.
- YOU MAY and should continue most allergy nasal sprays (i.e. Nasacort AQ, Rhinocort Aqua, Nasarel, Nasonex, Flonase, and Afrin), but NOT Astelin.
- YOU MAY and should use your asthma inhalers and these should be used as prescribed (i.e., Intal, Vanceril, Beclovent, Aerobid, Azmacort, Flovent, Serevent, Proventil, Maxair, Atrovent, Advair, Foradil, or Ventolin.
- YOU MAY continue oral steroid such as prednisone, and dexamethasone (Decadron) with the exception if you are scheduled for patch test. You cannot receive patch test until your system is totally clear of systemic steroids - usually 2 weeks after last dose.
- YOU MAY eat regularly on the day of testing and you should not skip any meals.
Due to the length of time required for testing, we request that parents do not bring small children with them to appointment unless child is to be tested.
We allot 2-4 hours for your evaluation, including history, physical exam, testing, educations, and planning your treatment of course. If we do not finish the testing, some of these plans will be at subsequent test visits. Do not cancel your appointment. The time set aside for you is exclusively yours. If you should need to change your skin test appointment, please give us at least a 48 hour notice.