AAO-HNSF Primary Care Otolaryngology Handbook

CHAPTER 9

which trigger other chemical mediators responsible for the late-phase allergic response (3–12 hours later), such as leukotrienes and prostaglandins. Allergy Testing Allergy testing allows for identification of specific allergens that may be the culprits in triggering the allergic response. Typically, patients under- going allergy testing are experiencing significant allergic reactions of unknown etiology and/or are refractory to empiric medical therapy. In some cases, patients preferring to avoid use of medications long term will undergo testing to guide immunotherapy to alter the immune system. Testing may be performed via in vitro or in vivo methods. In vitro testing, such as a radioallergosorbent test (RAST) is performed by testing the blood for allergen-specific IgE. RAST testing is not as sensitive as in vivo or skin testing but may provide useful information if positive. In vitro testing is preferred for patients who: • Are pregnant • Have poorly controlled asthma • Have dermatographism Skin testing for inhalant allergies can be performed via skin prick testing or intradermal testing . Allergens tested may vary based on the region in which the testing is performed and the preferred number of allergens tested within any given panel. Complications from allergy testing are extremely rare, but include local skin reactions to severe systemic reac- tions, such as anaphylaxis. Unlike blood testing, skin testing requires that antihistamine medications (oral or nasal) be discontinued about seven days before testing to avoid false negative results. Antileukotrienes, nasal steroid sprays, and decongestants may be continued without interfering with allergy skin testing. There are three mainstays of treating inhalant allergies: • Take a beta blocker medication • Take a tricyclic antidepressant • Take a monoamine oxidase inhibitor • Have a history of severe anaphylaxis

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• Allergen avoidance • Pharmacotherapy • Immunotherapy

Primary Care Otolaryngology