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Wise et al.

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Likewise, when 39 individuals with clinical cat allergy and negative SPT underwent a cat challenge, there was no difference in the development of upper respiratory symptoms between those who had positive or negative intradermal testing (24% vs 31%, p = 0.35). 793 Reddy et al. 857 evaluated allergy test results in 34 patients with perennial rhinitis. Patients with only intradermal positive skin tests (SPT negative) did not have a positive RAST nor a positive leukocyte histamine release. In contrast, SPT positivity was associated with positive RAST test and leukocyte histamine release assay. 857 Schwindt et al. 858 studied 97 subjects with allergic rhinoconjunctivitis symptoms. Prick testing was followed by intradermal testing if prick was negative. If patients were prick-negative and intradermal-positive, a nasal challenge was performed against 5 different allergens. If SPT with the multi-test II device was negative, only 17% of subjects had a positive intradermal test that corresponded with clinical history. None of these positive ID tests corresponded with a positive nasal challenge. 858 Taken together, these studies suggest that intradermal testing does not improve the diagnosis of allergy in subjects with negative SPT. Nevis et al. 830 conducted a systematic review of 4 studies to determine the sensitivity and specificity of intradermal testing when used as a confirmatory test following negative SPT. Sensitivity ranged from 27% (95% CI, 10% to 57%) to 50% (sample sizes were too small to calculate CI), while specificity ranged from 69% (95% CI, 51% to 83%) to 100% (95% CI, 83% to 100%). From a retrospective study by Larrabee and Reisacher, 859 when the clinician was guided by high clinical suspicion, the incidence of positive intradermal testing following negative SPT was 36.9% for indoor allergens ( D. pteronyssinus, D. farinae, cat, dog, and cockroach), 12.7% for outdoor allergens (ragweed, red birch, Timothy grass, white oak, and red maple) and 9.2% for molds ( Aspergillus, Candida, Penicillium, Alternaria, and Cladosporium ). However, no correlation between positive intradermal testing and nasal challenge testing was performed in this study. Escudero et al. 860 found that in rhinitis patients, SPT, intradermal and conjunctival challenge were more sensitive than serum sIgE. All testing methods had the same specificity. In summary, current evidence supports the use of intradermal testing for the diagnosis of AR due to airborne allergens as a stand-alone test, although this form of testing demonstrates no clear superiority over SPT when comparing sensitivity and specificity. There were no studies identified that directly compared single-dilution intradermal testing with IDT in terms of sensitivity, specificity, or patient outcomes. There appears to be a small gain in sensitivity when intradermal testing is used as a confirmatory test following negative SPT; however, positive intradermal test results in this setting could represent false-positive test results. It is also more likely that an intradermal test following a negative SPT will be positive when indoor allergens are being tested and least likely to be positive when testing for mold sensitivity. It is unknown whether the type of allergen has an impact on the sensitivity and specificity, as most studies examined used only 1 allergen, but intradermal testing seemed to be least sensitive and specific when mold was being tested. Other limitations of the studies identified for this review include low sample population sizes (the largest included 120 participants), variable study design, and the lack of randomized, controlled trials. • Aggregate Grade of Evidence: B (Level 1a: 1 study; Level 2b: 11 studies; Level 3b: 4 studies; Level 4: 1 study; Table VIII.E.2).

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