Patch Testing With Methylchloroisothiazolinone/Methylisothiazolinone Using a New Diagnostic Mix—A Multicenter Study From the International Contact Dermatitis Research Group. Issue 4 (July 2021)

• Record Type: Journal Article
• Authors: Isaksson, Marléne; Andersen, Klaus E.; Elsner, Peter; Goh, Chee-Leok; Gonçalo, Margarida; Goossens, An; Hadzavdic, Suzana Ljubojevic; Pratt, Melanie; Puangpet, Pailin; Sasseville, Denis; Verma, Kaushal; Bruze, Magnus
• Is Part Of: Dermatitis. Volume 32:Issue 4(2021)
• Publication Date: 2021-07
• Subjects: Skin -- Inflammation -- Periodicals; Skin -- Diseases -- Periodicals; Dermatology -- Periodicals; Dermatitis, Contact -- Periodicals; Dermatitis, Atopic -- Periodicals; Dermatitis, Occupational -- Periodicals; Drug Eruptions -- Periodicals; 616.51
• DOI: 10.1097/DER.0000000000000657
• Languages: English
• ISSNs: 1710-3568

Abstract

Abstract : Background: In the early 1980s, a preservative containing a mixture of methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) in a ratio of 3:1 was introduced. This mixture (mix) has been patch tested at 100 ppm (0.01%) worldwide and at 200 ppm (0.02%) in Sweden since 1986 and also in the European baseline series since 2014. Objective: A new aqueous mix of MCI 0.015% and MI 0.2% was compared with patch testing with the 2 aqueous baseline preparations of MCI/MI 0.02% and MI 0.2%. Methods: Four thousand three hundred ninety-seven patients with dermatitis in 12 International Contact Dermatitis Research Group dermatology departments from 3 continents were patch tested simultaneously with the 3 preparations. Results: The frequency of positive patch tests to the allergens varied between 0% and 26.7% in the 12 test centers. The new mixture MCI/MI 0.215% in aqua (aq) detected significantly more patients with MCI/MI allergy than both MCI/MI 0.02% aq ( P < 0.001) and MI 0.2% aq ( P < 0.001) alone and combined. Conclusions: The results favor replacing the preparations MCI/MI 0.02% aq and MI 0.2% aq with the mixture MCI/MI 0.215% aq in the International Contact Dermatitis Research Group baseline series.