Supplemental Patch Testing Identifies Allergens Missed by Standard Screening Series

Area of Science:

• Dermatology
• Allergology
• Immunology

Background:

• Standard patch testing is crucial for diagnosing allergic contact dermatitis.
• Supplemental patch testing serves as an adjunct to standard screening series.
• Identifying relevant allergens is key to effective patient management.

Purpose of the Study:

• To determine the demographics, characteristics, frequency, relevance, and interpretation of patch test reactions in supplemental patch testing.
• To evaluate the utility of supplemental patch testing in identifying allergens missed by standard North American Contact Dermatitis Group (NACDG) screening.
• To assess the prevalence of reactions to specific allergens within supplemental series.

Main Methods:

• Retrospective study of patients undergoing patch testing between 2017 and 2020.
• Utilized North American Contact Dermatitis Group (NACDG) and supplemental screening series (Supplemental Series A [SSA], Supplemental Series B [SSB]).
• Recorded demographics, dermatitis sites, reaction strengths, relevance, and final interpretation of patch test results.

Main Results:

• The study included 791 patients, with a majority being female (73.5%) and over 40 years old (68.6%).
• Significant percentages of patients showed positive reactions to SSA (11.7-13.5%) and SSB (31.5-38.1%) series.
• Of patients with negative NACDG testing, 12.1-19.5% had positive reactions to supplemental allergens, including those not in standard screening series.

Conclusions:

• Supplemental patch testing is effective in identifying relevant allergens missed by standard screening protocols.
• Specific allergens like dodecyl/octyl gallate and cinnamic alcohol were frequently identified in supplemental testing.
• This approach enhances the diagnosis of allergic contact dermatitis, particularly in cases with negative standard patch test results.