Sensitivity to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) has increased rapidly over recent years. This increase is mainly related to the extensive use of high concentrations of MI in cosmetic products, although a growing number of cases of occupational allergic contact dermatitis are caused by MCI/MI.
The aim of this study was to examine the association between the increase in MCI/MI sensitization and the work performed by the patients in our area.
A retrospective study was undertaken of the records of a total of 1179 patients who had undergone contact skin patch tests for MCI/MI from January 2005 to December 2015. A multivariate logistic regression analysis was performed to identify the factors independently associated with sensitivity to MCI/MI.
A constant increase in MCI/MI sensitization was observed over the observation period. The only work associated with a significant increase in the prevalence of MCI/MI sensitization was cleaning, with 38.5% of the cleaning professionals with MCI/MI sensitization consulting for cosmetics-related dermatitis.
Occupational sensitization to MCI/MI in cleaning professionals is worryingly increasing. This, in turn, could possibly account for many cases of cosmetics-associated contact dermatitis. Our findings suggest that a review of the regulations with regard to isothiazolinone concentrations in industrial and household detergents is necessary.
From the *Department of Dermatology, Complejo Hospitalario Universitario Insular Materno-Infantil, and †Mathematics, Universidad de Las Palmas de Gran Canaria; and ‡Department of Dermatology, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.
Address reprint requests to Gabriel Marrero-Alemán, MD, Department of Dermatology, Complejo Hospitalario Universitario Insular Materno-Infantil, Avda Marítima del Sur s/n, CP 35016, Gran Canaria, Spain. E-mail: firstname.lastname@example.org.
The authors have no funding or conflicts of interest to declare.