What Are Allergy Tests?

Allergy testing is performed to determine specific proteins to which you are allergic and to determine a safe starting dose for immunotherapy (allergy shots). For safety, we typically begin with a computerized breathing test for asthma. We may administer an inhaled breathing treatment with albuterol to determine if medication may help you to breathe more easily.

We then typically place 35 superficial pricks on the forearm, using a hand-held multiple prick device that places five antigens simultaneously. This step can be very itchy, but it is not terribly painful. After 20 minutes, we measure the size of the wheals, which look and feel like mosquito bites.

If you do not respond to the superficial prick, we will then place a larger dose of each antigen into the upper arm skin using a small hypodermic syringe. This step is less painful than expected, but does require you to hold still and be patient. Small children can be tested under anesthesia if ENT surgery is also necessary.

After 10 minutes more observation and measurement of the swelling, we may place a few confirmatory tests at a higher concentration. Our goal is to determine the concentration that produces a 7 mm wheal (swelling) for which the next stronger concentration produces a 9 mm or larger wheal. This concentration has been shown to be the strongest safe starting dose for immunotherapy (allergy shots).

If you cannot undergo testing due to illness, medication, poorly reactive skin or inability to cooperate, we can submit a blood sample to the laboratory for testing. This test is often called a RAST test, based on the acronym for older forms of the test. Blood testing is more expensive, less sensitive, and takes longer to receive results than skin testing. Blood tests do provide concentrations of antigen-specific immunoglobulin E that can be used to estimate safe starting doses for immunotherapy.

Risks of Allergy Testing

The risks of testing include minor discomfort, as well as the possibility of more serious allergic reactions (anaphylaxis). These symptoms may include throat swelling, shortness of breath, wheezing, vocal cord spasm, flushing of skin, fainting, collapse and death. The risk of death is as unlikely as the risk of dying in an automobile accident. More common reactions include typical allergy symptoms such as itching of the skin, nose or mouth, runny nose, nasal congestion, watery red eyes, and coughing.

If any of these mild generalized reactions occur during the test, we will stop immediately and postpone further testing to another day. For your safety, our office is equipped with appropriate resuscitation equipment for rare allergy emergencies, and our providers are trained in emergency management. Our physicians are personally available in the office during all allergy testing and allergy shots. Occasionally, testing or treatment is performed in the surgery center next door, with back-up from the anesthesiologists. We use sterile, disposable needles and have never seen an infection after testing, but we recommend that you bathe well before the test and not vigorously scratch after you leave.

Patients who take beta blocker medications, commonly prescribed for high blood pressure, heart disease, migraines or glaucoma, are at increased risk during allergy testing and immunotherapy. We may also want to postpone testing if you are or might be pregnant, acutely ill, suffering from uncontrolled asthma, or have a rash on your skin.

Instructions Before Allergy Testing

We generally schedule allergy tests one week in advance. Please allow at least two hours for the visit, and understand that you may have some itching or other discomfort for a few hours after the test. Eat normally before your test, and bring a book or music if you wish. Wear a short sleeved or sleeveless shirt. Take your usual asthma medications and nasal steroids, but stop all antihistamines one week before testing. Certain heart medications increase the risk of testing. Please review the lists carefully now and let us know if any of the following apply:

Please advise us immediately if:

  • You may be pregnant
  • You are feeling sicker than usual
  • You have recently been to the ER
  • You use albuterol more than once daily
  • You have had a severe reaction to bee stings
  • You have a current skin disorder or rash
  • You have had any serious allergic reaction
  • You take B-blockers, antidepressants or antacids

Stop all antihistamines 7 days before skin testing:

  • All cough, cold or allergy combinations
  • Actifed (chlorpheniramine)
  • Alavert (loratidine)
  • Allegra (fexofenadine)
  • Astelin/Astepro (azelastine)
  • Atarax (hydroxyzine)
  • Axid (nizatidine)
  • Benadryl (diphenhydramine)
  • Clarinex (desloratidine)
  • Claritin (loratidine)
  • Coricidin (chlorpheniramine )
  • Dymista (azelastine/fluticasone)
  • Dimetapp (brompheniramine)
  • Lodrane (brompheniramine)
  • Patanase (olapatadine)
  • Pepcid (famotidine)
  • Periactin (cyproheptadine)
  • Phenergan (promethazine)
  • Tagamet (cimetidine)
  • Tavist (clemastine)
  • Vistaril (hydroxyzine)
  • Xyzal (levocetirizine)
  • Zantac (ranitidine)
  • Zyrtec (cetirizine)

CALL US immediately if you are taking ANY of these beta blocker medications:

  • Betapace (Sotalol)
  • Blocadren (Timolol)
  • Brevibloc (Esmolol)
  • Bystolic (Nebivolol)
  • Coreg (Carvedilol)
  • Corgard (Nadolol)
  • Cartrol (Carteolol)
  • Inderal (Propranolol)
  • Kerlone (Betaxolol)
  • Levatol (Penbutolol)
  • Lopressor (Metoprolol)
  • Normodyne (Labetalol)
  • Sectral (Acebutolol)
  • Tenormin (Atenolol)
  • Toprol XL (Metoprolol)
  • Trandate (Labetalol)
  • Visken (Pindolol)
  • Zebeta (Bisoprolol)

Eye Drops:

  • Betagan (Levobunolol)
  • Ocupress (Carteolol)
  • Betoptic (Betaxolol)
  • Timoptic (Timolol)
  • Emadine (emadastine)
  • Livostin (levocabastine)
  • Optivar (azelastine)
  • Patanol/Pataday (olopatadine)
  • Zaditor (ketotifen)