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Wise et al.

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testing. Reviewing the available literature, a preponderance of benefit over harm for SPT exists. Therefore, the use of SPT is recommended in situations where the diagnosis of AR needs to be supported or a patient with presumed AR has failed appropriate empiric medical therapy. • Aggregate Grade of Evidence: B (Level 1a: 1 study; Level 3b: 7 studies; Table VIII.E.1). • Benefit: Supports diagnosis and directs pharmacological therapy while possibly avoiding unnecessary/ineffective treatment; guides avoidance; directs AIT. • Harm: Adverse events from testing including discomfort, pruritus, erythema, worsening of asthma symptoms, and anaphylaxis, inaccurate test results, and misinterpreted test results. • Cost: Low. • Benefits-Harm Assessment: Preponderance of benefit over harm. • Value Judgments: Patients can benefit from identification of their specific sensitivities. SPT is a quick and relatively comfortable way to test several antigens with accuracy similar to other available methods of testing. • Policy Level: Recommendation. • Intervention: SPT is recommended for evaluation of allergen sensitivities in appropriately selected patients. Regular use of the same SPT device will allow clinicians to familiarize themselves with it and interpretation of results may therefore be more consistent. The use of standardized allergen extracts can further improve consistency of interpretation. VIII.E.2. Skin intradermal testing— The placement of allergenic proteins in the intradermal space is often used for diagnosing AR. Intradermal testing has also been described in the evaluation of sensitivities to other substances, including local anesthetic agents, neuromuscular blocking agents, antibiotics, and contrast media. 837-840 While previous protocols have described the use of intradermal testing for suspected food or chemical allergies, this type of diagnostic testing is currently not recommended in routine practice. 841,842 Intradermal testing may be used as a primary testing modality, or as a secondary test following SPT. Intradermal testing has also been used, primarily by otolaryngic allergists, as a method to help determine the starting point for specific AIT and as a vial safety test prior to an injection from a new treatment vial, though the level of evidence supporting these uses is low. 843,844 Intradermal testing may be performed as a single injection. A short bevel needle is used to inject a diluted allergenic extract solution into the superficial dermis. Approximately 0.02 mL is used, or enough to produce a well-defined wheal, which is 4 mm in diameter. 845 The wheal will expand to 5 mm by hydrostatic forces, and the reaction is observed for 10 minutes. The positive control for intradermal testing is histamine and the negative controls are typically phenolated saline and a glycerin solution that equals the concentration of glycerin in the test solution. If the diameter of the resulting wheal is at least 7 mm, and at

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