Background: There has been an increase in methylchloroisothiazolinone (MCI) and especially methylisothiazolinone (MI) contact allergy in recent years.
Objectives: We examined the prevalence and demography of MCI/MI and MI contact allergy in patients presenting with facial dermatitis.
Methods: Eighty patients with facial dermatitis were patch tested to the British Society for Cutaneous Allergy standard series, preservatives and own products between January 2012 and March 2014.
Results: A total of 14 (17.5%) patients had positive reactions to this preservative. Five (6.3%) patients tested positive to MCI/MI (0.02%), four (5%) patients tested positive to MI (0.2%) and five (6.3%) patients tested positive to both preparations. Six (7.5%) of these patients were atopic. All patients were female and the mean age was 53.8 years. Sources of allergen were in cosmetics and skin care products.
Conclusions: Contact allergies to MCI/MI and MI are commoner than what was reported before and is an emerging cause of facial dermatitis. The detection rate of this allergen was increased by 5% in our cohort since the inclusion of MI (0.2%) in the standard series.
© 2015 European Academy of Dermatology and Venereology.