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Wise et al.

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• Benefit: Confirms sensitization in support of an AR diagnosis and directs appropriate therapy while possibly avoiding unnecessary/ineffective treatment; guides avoidance measures; and directs AIT. • Harm: Adverse events from testing including discomfort from blood draw, inaccurate test results, false-positive test results, misinterpreted test results. • Cost: Moderate cost of testing. • Benefits-Harm Assessment: Preponderance of benefit over harm. • Value Judgments: Patients can benefit from identification of their specific sensitivities. Further, in some patients who cannot undergo skin testing, sIgE testing is a safe and effective alternative. • Policy Level: Recommendation. • Intervention: Serum sIgE testing may be used in the evaluation of AR. Using standardized allergens and rigorous proficiency testing on the part of laboratories may improve accuracy. VIII.F.3. Correlation between skin and in vitro testing— Allergen skin testing has been used to diagnose allergic disease since first introduced by Blackley 140 years ago. 791,928 The discovery of IgE in 1969 allowed for the development of in vitro serological tests which have become increasingly utilized. 929 However, skin testing and sIgE serology portend unique biological functions. Therefore, the 2 tests are not fully interchangeable. Modern SPT of aeroallergens can be up to 25% more sensitive than sIgE serology depending on the patient population and the methodologies employed. 793,930-934 In the United States, SPT also generally costs about one-half as much as sIgE serology ($6.82 vs $12.50 per allergen tested). 935 Other factors to consider include access to laboratory technology, comorbid disease, and the age of the patient. In vitro testing avoids the need to withhold medications that affect skin testing and allows for testing in subjects with dermatographism or other widespread skin disorders. SPT measurements are directly observable within 20 minutes, which is typically much faster than laboratory reports are obtained. Both sIgE serology and SPT are considered very safe techniques; however, SPT does carry a very small risk of anaphylaxis. The sensitivity and specificity of SPT depends on the allergen tested, quality of reagents, the specific methodologies employed, technician expertise, and patient demographics. 928,937-942 For example, SPT wheal size and sensitivity depend on the specific device selection and the choice of control reagents used for testing. 928,938 Nonetheless, a recent meta-analysis indicates that SPT remains an accurate test, which when combined with a detailed clinical history, helps confirm the diagnosis of AR 830 (Table VIII.F.3-1). The performance and reliability of serum sIgE testing likewise depends on several factors including the choice of reagents, modernization of equipment, and patient demographics. 932 The cutoff value for a positive test affects both the sensitivity and specificity. 943 In a Korean population, SPT was found to be superior to ImmunoCAP for measuring dust mite

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Int Forum Allergy Rhinol . Author manuscript; available in PMC 2020 June 10.