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Wise et al.

Page 67

Leukotriene receptor antagonists (LTRAs) do not appear to interfere with allergy skin test results. Hill and Krouse 876 as well as Simons et al. 866 found no effect of montelukast on intradermal skin test results in allergic subjects. Cuhadaroglu et al. 877 found no change in SPT results in allergic subjects before and treatment with zafirlukast. In general, the highest level evidence shows that systemic steroid treatment has no effect on SPT and intradermal test results, 878,879 though some less rigorous retrospective studies suggest that systemic steroid treatment could affect skin whealing responses. 880,881 Topical steroid treatment has been demonstrated to suppress the wheal and flare reaction in treated skin areas, creating the possibility of false-negative test results. 882-885 No studies were identified that examined the effect of intranasal or inhaled steroids on skin test results. The effects of many classes of medications on allergy skin test responses remain inadequately studied. Benzodiazepines have been implicated as possibly suppressing skin test responses. 886,887 The calcineurin inhibitor tacrolimus was shown to inhibit SPT whealing, 885 whereas a study of a similar drug, pimecrolimus, did not show any effect on skin whealing responses. 888 The pharmacologic effects of herbal preparations are generally unstudied, and it is unclear which of these agents could interfere with allergy skin test responses. More et al. 889 performed a double-blind, placebo-controlled, single-dose crossover study in 15 healthy volunteers, examining the histamine-induced skin test response. None of the 23 herbal supplements tested caused suppression of the histamine induced wheal response. There are many classes of medications for which the actual impact on allergy skin testing are unknown. To mitigate against the risk of false-negative skin test results induced by medications, all allergy testing should be performed after application of appropriate positive controls (usually histamine) to ensure that the histamine-induced skin test reaction is intact at the time of testing. See Table VIII.E.4.a-1 for a comprehensive review, with Aggregate Grades of Evidence in Table VIII.E.4.a-2. VIII.E.4.b. Skin conditions.: The usefulness of allergy skin testing depends upon the ability to detect a Type I hypersensitivity reaction after allergen introduction into the skin. Abnormal skin (eg, dermatitis) may not respond appropriately to histamine, glycerin, or allergen. Additionally, the physical trauma of prick/puncture or intradermal testing may induce a local inflammatory response. The wheal and flare reaction also may be difficult to detect due to preexisting skin changes. Further, skin color may inhibit the ability to visualize the flare reaction, especially in darker skinned individuals. Common sense dictates that allergy skin testing should not be performed at sites of active dermatitis, but clinical studies to investigate this phenomenon are lacking. Individuals with dermatographism may have exaggerated responses to allergy skin testing, requiring close attention to the results of negative control tests. In some cases, it may be preferable to perform in vitro specific IgE testing in patient with skin disease or dermatographism, but this is not based on data or outcomes from controlled studies.

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