Results of patch testing to personal care product allergens in a standard series and a supplemental cosmetic series: An analysis of 945 patients from the Mayo Clinic Contact Dermatitis Group, 2000-2007

Background: Patch testing to a standard screening series of allergens in combination with supplemental cosmetic allergens is often used to diagnose allergic contact dermatitis due to personal care products. Objective: To report results of patch testing to skin care product allergens contained in a standard series and a supplemental cosmetic series and to compare efficacy of this combined series in detecting positive reactions to personal care product allergens with the efficacy of various standard screening series. Methods: Positive reaction rates to skin care product allergens were tabulated for patients who underwent patch testing to both standard and cosmetic series allergens at Mayo Clinic between 2000 and 2007. Data were compared with skin care allergens detected on standard screening series, including the thin-layer rapid use epicutaneous (TRUE) test. Results: Of 945 patch-tested patients, 68.4% had at least one positive reaction and 47.3% had at least two positive reactions. Also, 49.4% of patients reacted to at least one preservative; 31.2% reacted to at least one fragrance/botanical additive. Compared with use of our standard series and cosmetic series, use of the TRUE test would have missed 22.5% of patients with preservative allergy, 11.3% with fragrance/botanical allergy, and 17.3% with vehicle allergy. Limitations: Various allergens tested over time, patch test reading by residents, and lack of confirmation of allergen in personal care products. Conclusion: Standard patch-test screening series miss a substantial number of patients with skin care product ingredient allergy.