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How do I know if the testing being done to evaluate my allergic symptoms is appropriate?
By definition, a substance that is capable of causing allergic symptoms in sensitized individuals is called an allergen. Any biological extract selected for use in an “allergy test” should have been proven in scientific studies to be “clinically relevant”. Allergens used by San Antonio Allergists for routine skin testing to detect airborne respiratory allergies include extracts of: trees, grasses, and weed pollens, molds, dust mites, cockroach and pet danders. The specific allergens selected for testing by Allergists are all known to be present in our local environment. The inclusion of an allergen on a test panel conveys to the patient the physician’s impression that it is potentially “clinically relevant”. For example, pine trees are very common in Houston Texas; and so pine tree pollen is typically seen on allergy testing panels in that area of Texas. Conversely, trees such as pine and birch do not grow well in San Antonio, and therefore are not included on the allergy screening panels used by San Antonio Allergists. All airborne allergens selected for routine skin testing by Allergists have been studied by clinical scientists and have been used safely and effectively for immunotherapy (allergy shots). There are many extracts that are commercially produced and called “allergy testing” reagents however, all available extracts are not considered to be “clinically relevant”. For this reason, routine skin testing with extracts of tobacco, moth, housefly, mosquito, flea and deerfly, is not done by Allergists. In addition, the only species of fire ants that is indigenous to Texas is Solenopsis invicta and so testing for Solenopsis richterii is not performed. Allergy testing to clinically irrelevant antigens provides no clinical benefit to the patient and needlessly drives up the cost of an “allergy” evaluation.
Is skin testing safe?
Although very rare, skin testing can cause allergic reactions (anaphylaxis). When allergic reactions do occur from prick (scratch) skin testing, they are typically mild and non-progressive however; a death from a skin testing has been reported. The Texas Medical Board requires that all patients who undergo any medical test or procedure that places them at risk for injury or death should be informed by their physician of this risk. All Allergists in Texas provide their patients with a written “consent for treatment” prior to skin testing that outlines the risks and benefits of skin testing and also includes information on alternative allergy evaluation methods (i.e. RAST). The risk of allergic reactions to skin testing may be slightly different for each Allergist due to the different types of skin testing devices available for use. In addition, not all allergists purchase allergy extracts from the same manufacturers, and this variable can also affect the risk for reactions. The evidence-based, broadly accepted guidelines for the appropriate use of skin testing for the diagnosis of allergy, and the use of “allergy shots” for the treatment of allergies are available at www.jcaai.org . These “Practice Parameters” were developed by the Joint Task Force (JTF) with the goal of improving the quality of care provided by Allergists in the USA. The Joint Task Force (JTF) is comprised of representatives from the American Academy and the American College of Allergy, Asthma and Immunology (AAAAI/ACAAI) as well as the Joint Council of Allergy Asthma & Immunology (JCAAI). These “Practice Parameters” are updated periodically and were most recently published in the Annals of Allergy, Asthma & Immunology, March 2008; vol.100, number 3, Supplement 3, pages S2-S148 (Allergy Diagnostic Testing: An Updated Practice Parameter). All San Antonio Allergists follow the recommendations of the JTF closely because these guidelines were developed after careful review of the most reliable clinical information available. As determined by the JTF, skin testing by the prick/scratch method is the preferred technique for the diagnosis of allergy caused by allergic antibodies (IgE) and shows better predictability for the diagnosis of inhalant allergy than blood testing techniques such as RAST testing.
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