Allergic or Not: Final Interpretation of Doubtful Patch Test Reactions From the North American Contact Dermatitis Group, 2019-2020

Authors

Margo J. Reeder, From the Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Aman Nihal, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Srikanth R. Aravamuthan, From the Department of Dermatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
Erin M. Warshaw, Department of Dermatology, Park Nicollet Health Services, Minneapolis, Minnesota, USA.
Joel G. DeKoven, Division of Dermatology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada.
Amber R. Atwater, Department of Dermatology, Duke University Medical Center, Durham, North Carolina, USA.
Marie-Claude Houle, Division of Dermatology, CHU de Quebec, Laval University, Quebec City, Quebec, Canada.
Brandon L. Adler, Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Jonathan I. Silverberg, Department of Dermatology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.
James S. Taylor, Department of Dermatology, Cleveland Clinic, Cleveland, Ohio, USA.
Melanie D. Pratt, Division of Dermatology, University of Ottawa, Ontario, Canada.
Donald V. Belsito, Department of Dermatology, Columbia University Irving Medical School, New York, New York, USA.
Jiade Yu, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Nina B. Botto, Department of Dermatology, University of California, San Francisco, California, USA.
Chris M. Mowad, Department of Dermatology, Geisinger Medical Center, Danville, Pennsylvania, USA.
Cory A. Dunnick, Department of Dermatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; and.
Vincent A. DeLeo, Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.

Document Type

Journal Article

Publication Date

1-1-2024

Journal

Dermatitis : contact, atopic, occupational, drug

Volume

35

Issue

2

DOI

10.1089/derm.2023.0285

Abstract

Doubtful patch test reactions generally do not meet criterion for positivity in patch testing. However, the North American Contact Dermatitis Group (NACDG) allows for doubtful reactions to be coded with a final determination of "allergic/positive" based on the temporal pattern, appearance, known characteristics of the allergen, and/or other supportive patch test reactions. To analyze NACDG data from the 2019-2020 patch test cycle to identify patterns in the interpretation and relevance of doubtful reactions. The frequency and proportions of doubtful reactions were tabulated and analyzed for patterns. Statistical analyses were limited to allergens with ≥30 doubtful reactions to ensure adequate sample size. Of patch-tested patients, 31.9% (1315/4121) had ≥1 doubtful reaction. Of 2538 total doubtful reactions, 46% (n = 1167) had a final interpretation of "allergic/positive." The allergens with the highest proportion of doubtful reactions at the final visit were hydroperoxides of linalool 1% (4.5%), fragrance mix I 8.0% (3.9%), and cetrimonium chloride 0.5% (3.4%). Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) 0.02% ( < 0.001), MI 0.2% ( < 0.001), nickel sulfate hexahydrate 2.5% ( = 0.001), and neomycin sulfate 20.0% ( = 0.003) doubtful reactions were more likely to be interpreted as allergic than nonallergic. Methyldibromoglutaronitrile/phenoxyethanol 0.2% ( < 0.001), oleamidopropyl dimethylamine 0.1% ( < 0.001), formaldehyde 2.0% ( < 0.001), cetrimonium chloride 0.5% ( < 0.001), benzophenone-4 (sulisobenzone) 10% ( < 0.001), iodopropynyl butylcarbamate 0.5% ( < 0.001), cocamidopropyl betaine 1.0% ( = 0.002), and benzisothiazolinone 0.1% ( = 0.012) doubtful reactions were less likely to be interpreted as allergic. Of the 1167 doubtful reactions interpreted as allergic, 84.9% had current relevance. Doubtful reactions were common and approximately one half were coded with a final interpretation of "allergic/positive." Of those, most were clinically relevant. MCI/MI, MI, nickel, and neomycin were more likely to be interpreted as allergic.

APA Citation

Reeder, Margo J.; Nihal, Aman; Aravamuthan, Srikanth R.; Warshaw, Erin M.; DeKoven, Joel G.; Atwater, Amber R.; Houle, Marie-Claude; Adler, Brandon L.; Silverberg, Jonathan I.; Taylor, James S.; Pratt, Melanie D.; Belsito, Donald V.; Yu, Jiade; Botto, Nina B.; Mowad, Chris M.; Dunnick, Cory A.; and DeLeo, Vincent A., "Allergic or Not: Final Interpretation of Doubtful Patch Test Reactions From the North American Contact Dermatitis Group, 2019-2020" (2024). GW Authored Works. Paper 4606.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/4606

Department

Dermatology