The epidemic of methylisothiazolinone: a European prospective study

Contact Dermatitis. 2017 May;76(5):272-279. doi: 10.1111/cod.12733. Epub 2016 Dec 28.

Abstract

Background: The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required.

Objectives: To describe demographics and MI exposures for European patients with MI contact allergy.

Methods: Eleven European dermatology departments from eight European countries prospectively collected data between 1 May and 31 October 2015 among consecutive patients who had positive patch test reactions to MI (2000 ppm aq.).

Results: A total of 6.0% (205/3434; range 2.6-13.0%) of patients had positive patch test reactions to MI. Dermatitis most frequently affected the hands (43.4%), face (32.7%), arms (14.6%), and eyelids (11.7%); 12.7% had widespread dermatitis. For 72.7% (149/205), MI contact allergy was currently relevant mainly because of exposure to cosmetic products (83.2%; 124/149). Of these 124 patients, 19.5% were exposed to leave-on and rinse-off cosmetic products, 24.8% only to leave-on cosmetic products and 38.9% only to rinse-off cosmetic products containing MI or methylchloroisothiazolinone/MI. The majority of these (79%) noted onset of their dermatitis between 2013 and 2015. Fifteen patients (7.3%) had previously experienced allergic reactions when they were in newly painted rooms.

Conclusion: Clinically relevant MI contact allergy remains prevalent across European countries, mainly because of exposure to rinse-off and leave-on cosmetic products.

Keywords: CAS no. 2682-20-4; allergic contact dermatitis; cosmetics; exposure; methylchloroisothiazolinone; methylisothiazolinone.

MeSH terms

  • Dermatitis, Allergic Contact / epidemiology*
  • Dermatitis, Occupational / epidemiology*
  • Europe
  • Facial Dermatoses / chemically induced
  • Hand Dermatoses / chemically induced
  • Humans
  • Leg Dermatoses / chemically induced
  • Preservatives, Pharmaceutical / administration & dosage
  • Preservatives, Pharmaceutical / adverse effects*
  • Prospective Studies
  • Thiazoles / administration & dosage
  • Thiazoles / adverse effects*

Substances

  • Preservatives, Pharmaceutical
  • Thiazoles
  • 2-methyl-4-isothiazolin-3-one