Reliability of Expired Allergens in Patch Testing: A Comparative Study With Non-Expired Series

NCT07765563 | Not Yet Recruiting Phase 4

• 1 other identifier: REB26-0539
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

Patch testing remains the gold standard in the diagnosis of allergic contact dermatitis. Patches used in testing consist of a wide spectrum of allergens, with variability in the stability of products over time. Due to limited allergen stability, careful storage and preparation is needed to prevent product degradation over time. Expiration dates are provided by manufacturers to ensure stability and reactivity, while minimizing the risk of product degradation contributing to inaccurate testing results. Preparation of patch series can be time intensive and procurement of allergens comes with an associated economic burden. Expired allergens are not routinely used in patch testing, however many clinics have expired allergens accessible. There is paucity of evidence comparing the reactivity of expired vs non-expired patch series. If expired allergens remain effective, this could result in significant cost-savings and accessibility implications for dermatology practice.

Conditions

Allergic Contact Dermatitis

Keywords

contact dermatitis; patch testing

Outcome Measures

Primary Outcomes (1)

• Patch Testing Response (Positive/Negative) Concordance Rate (%) Between Non-Expired and Expired Allergens

  Each allergen will be graded on response using a standard patch test scale including: irritant reaction \['IR'\], '+/-' for doubtful, '+' for erythema and infiltration, '++' for edematous or vesicular and '+++' for spreading, bullous or ulcerative response that will be graded by the participating Dermatologist. Reactions graded '+', "++", or "+++" are consider a positive result. Concordance rate will be expressed as a percentage (%) between tested allergens that were non-expired and that were expired (i.e. Nickel sulfate hexahydrate was found to have a 92% concordance rate, meaning that in 92% of cases, the Nickel allergen in the non-expired and expired patches were both found to both be either positive or negative while in 8% of cases the response differed per the scale listed above.)

  Standard patch test series are applied on Day 0. Participant removal of patches on Day 2 and self photos taken and sent to Dermatologist for virtual reading. Final reading completed in clinic by Dermatologist on Day 4 or 5, recording reaction scores.

Secondary Outcomes (3)

• Reaction/Morphology Scoring Concordance (%)

  Standard patch test series are applied on Day 0. Participant remove patches on Day 2, photos taken and sent to Dermatologist for virtual reading. Final reading completed in clinic by Dermatologist on Day 4 or 5, recording reaction scores, morphology.

• Stability Concordance (%) Amongst Mediums

  Standard patch test series are applied on Day 0. Participant remove patches on Day 2, photos taken and sent to Dermatologist for virtual reading. Final reading completed in clinic by Dermatologist on Day 4 or 5, recording reaction scores, morphology.

• Irritant Reaction Rates (%)

  Standard patch test series are applied on Day 0. Participant remove patches on Day 2, photos taken and sent to Dermatologist for virtual reading. Final reading completed in clinic by Dermatologist on Day 4 or 5, recording reaction scores, morphology.

Study Arms (1)

Enrolled Study Participants

OTHER

All enrolled participants will be simultaneously patch tested with both expired and non-expired patches. Therefore, there is no difference in intervention amongst study participants.

Biological: Patch 1 (Expired); Biological: Patch 2 (non-expired)

Interventions

Patch 1 (Expired) BIOLOGICAL

All enrolled participants will be simultaneously patch tested with both expired and non-expired patches. Therefore, there is no difference in intervention amongst study participants.

Enrolled Study Participants

Patch 2 (non-expired) BIOLOGICAL

All enrolled participants will be simultaneously patch tested with both expired and non-expired patches. Therefore, there is no difference in intervention amongst study participants.

Enrolled Study Participants

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults (age 18 years or older) referred for patch testing.

You may not qualify if:

• Relative or absolute contraindication to patch testing
• Wide spread dermatitis prior to patch placement
• Inability to return to clinic for reading of results
• Patient non-consenting

Sponsors & Collaborators

• University of Calgary: lead

Study Sites (1)

Richmond Road Diagnostic Treatment Centre

Calgary, Alberta, T2T 5C7, Canada

Location

Related Publications (9)

• Houle MC, DeKoven JG, Atwater AR, Reeder MJ, Warshaw EM, Pratt MD, Belsito DV, Adler BL, Silverberg J, Yu J, Botto N, Mowad CM, Dunnick CA, Taylor JS. North American Contact Dermatitis Group Patch Test Results: 2021-2022. Dermatitis. 2025 Sep-Oct;36(5):464-476. doi: 10.1089/derm.2024.0474. Epub 2025 Apr 24.

  PMID: 40274377 RESULT

• Schalock PC, Dunnick CA, Nedorost S, Brod B, Warshaw E, Mowad C, Scheman A; American Contact Dermatitis Society Core Allergen Series Committee. American Contact Dermatitis Society Core Allergen Series: 2020 Update. Dermatitis. 2020 Sep-Oct;31(5):279-282. doi: 10.1097/DER.0000000000000621.

  PMID: 32947457 RESULT

• Siegel PD, Fowler JF, Law BF, Warshaw EM, Taylor JS. Concentrations and stability of methyl methacrylate, glutaraldehyde, formaldehyde and nickel sulfate in commercial patch test allergen preparations. Contact Dermatitis. 2014 May;70(5):309-15. doi: 10.1111/cod.12169.

  PMID: 24731086 RESULT

• Mowitz M, Svedman C, Zimerson E, Bruze M. Fragrance patch tests prepared in advance may give false-negative reactions. Contact Dermatitis. 2014 Nov;71(5):289-94. doi: 10.1111/cod.12300. Epub 2014 Sep 18.

  PMID: 25231568 RESULT

• Mose KF, Andersen KE, Christensen LP. Stability of selected volatile contact allergens in different patch test chambers under different storage conditions. Contact Dermatitis. 2012 Apr;66(4):172-9. doi: 10.1111/j.1600-0536.2011.02035.x.

  PMID: 22404192 RESULT

• Goon AT, Bruze M, Zimerson E, Sorensen O, Goh CL, Koh DS, Isaksson M. Variation in allergen content over time of acrylates/methacrylates in patch test preparations. Br J Dermatol. 2011 Jan;164(1):116-24. doi: 10.1111/j.1365-2133.2010.10087.x.

  PMID: 21039407 RESULT

• Johansen JD, Aalto-Korte K, Agner T, Andersen KE, Bircher A, Bruze M, Cannavo A, Gimenez-Arnau A, Goncalo M, Goossens A, John SM, Liden C, Lindberg M, Mahler V, Matura M, Rustemeyer T, Serup J, Spiewak R, Thyssen JP, Vigan M, White IR, Wilkinson M, Uter W. European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice. Contact Dermatitis. 2015 Oct;73(4):195-221. doi: 10.1111/cod.12432. Epub 2015 Jul 14.

  PMID: 26179009 RESULT

• Rodrigues Barata AR, Haroun-Diaz E, Conde-Salazar Gomez L. Can expired TRUE Test(R) be used for patch testing? Contact Dermatitis. 2014 Jun;70(6):381-2. doi: 10.1111/cod.12175. No abstract available.

  PMID: 24846590 RESULT

• Mahajan VK, Chauhan PS, Mehta KS, Sharma A, Chowdhary B, Dhattarwal N, Sharma H, Chandel M, Verma YR. Patch testing with expired Indian patch test kits: Results of a pilot study. Indian J Dermatol Venereol Leprol. 2022 Mar-Apr;88(2):188-195. doi: 10.25259/IJDVL_390_19.

  PMID: 33969657 RESULT

MeSH Terms

Conditions

Dermatitis, Allergic Contact; Dermatitis, Contact

Interventions

Exhalation

Condition Hierarchy (Ancestors)

Dermatitis; Skin Diseases; Skin and Connective Tissue Diseases; Skin Diseases, Eczematous; Hypersensitivity, Delayed; Hypersensitivity; Immune System Diseases

Intervention Hierarchy (Ancestors)

Respiratory Mechanics; Respiration; Respiratory Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena

Study Officials

• Laurie Parsons, Medical Doctor

  University of Calgary

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Dylan Hollman, Medical Doctor

CONTACT

1-403-955-8444; dylan.hollman@ucalgary.ca

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Masking Details: No masking is needed given data is all observational and based on clinical response.
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principle Investigator

Model Details: All participants will receive patch testing with both the expired and non-expired patches.

Study Record Dates

• First Submitted: July 7, 2026
• First Posted: August 14, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: August 14, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)