The frequency of positive reactions to 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (MCI/MI) were studied at 22 European contact dermatitis clinics over a period of 1 year. A total of 4713 patients participated. All the patients were patch tested with nickel sulphate, formaldehyde, paraben-mix, and MCI/MI. 19.4% of the patients had positive patch tests to nickel, making this the most common allergen. 3% of the patients reacted to 100 ppm MCI/MI, while 2.6% reacted to formaldehyde and 1.1% to parabens. There was great variation in the frequency of MCI/MI sensitivity among the 22 centres. MCI/MI contact allergy was most common among women and in patients with facial dermatitis, while it was rarely seen in patients with dermatitis on the lower legs. There were no fluctuations in the number of positive patch tests to MCI/MI on a monthly basis when the results from all centres were combined. 117 of the 141 MCI/MI sensitized patients included in the study were retested. 88% had positive patch tests when retested. 101 of the MCI/MI-sensitive patients participated in a double-blind, placebo-controlled product use test. This test showed that 31% of the MCI/MI-sensitive patients had a positive reaction to a MCI/MI-preserved product. Only a few patients reacted to a control product. It is concluded that the preservative MCI/MI is an important new contact allergen.
Adams Robert M., Maibach Howard I., Adams Robert M., Maibach Howard I., Clendenning W.E., Fisher A.A., Jordan W.J., Kanof N., Larsen W., Mitchell J.C., Rudner E.J., Schorr W., Storrs F., Taylor J.S., Eiermann Heinz J., Marzulli Frank N., A five-year study of cosmetic reactions, 10.1016/s0190-9622(85)70258-7
Chan Ping Kwong, Baldwin Robert C., Parsons Richard D., Moss Jack N., Stiratelli Robert, Smith Jerry M., Hayes A. Wallace, Kathon Biocide: Manifestation of Delayed Contact Dermatitis in Guinea Pigs Is Dependent on the Concentration for Induction and Challenge, 10.1111/1523-1747.ep12522544
Björkner Bert, Bruze Magnus, Dahlquist Inger, Fregert Sigfred, Gruvberger Birgita, Persson Karin, Contact allergy to the preservative Kathon® CG, 10.1111/j.1600-0536.1986.tb01166.x
Cronin E., Hannuksela M., Lachapelle J. M., Maibach H. I., Malten K., Meneghini C. L., Frequency of sensitisation to the preservative Kathon® CG, 10.1111/j.1600-0536.1988.tb02832.x
Cronin, Preservatives and antibacterials in contact dermatitis (1980)
Bibliographic reference
Menne, T. ; Frosch, PJ. ; Veien, NK. ; Hannuksela, M. ; Bjorkner, B. ; et. al. Contact Sensitization To 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (mci/mi) - a European Multicenter Study. In: Contact Dermatitis : environmental and occupational dermatitis, Vol. 24, no. 5, p. 334-341 (1991)
