Quantitative relationships between patch test reactivity and use test reactivity: an overview

Abstract

Use tests such as the provocative use test (PUT) or repeated open application test (ROAT) have been created to better understand the clinical significance of patch test results. It has been suggested that since these tests typically utilize only one substance at a time and avoid occlusion, they minimize the occurrence of irritation and false positives and, thus, are more reflective of real-life exposure to an allergen. In this analysis, we compare and analyze different studies comparing patch test and use test reactivity. With regard to colophony, cinnamic aldehyde, methyldibromo glutaronitrile, 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, and isoeugenol, increased patch test sensitivity resulted in increased use test sensitivity. However, this was not true for formaldehyde or chromium. The reason for the latter allergens’ divergence from the trend is not yet understood. Additionally, we note the presence of an increasing slope in the relationship between use test reactivity and minimum eliciting concentration on patch testing for methyldibromo glutaronitrile. Expansion of databases relating serial dilution patch test reactivity and use test data should aid dermatologic management, public health policy, and an understanding of the complexity of allergic contact dermatitis in humans.