This patient information on Methylchloroisothiazolinone/Methylisothiazolinone is provided by John L. Meisenheimer, M.D. a board certified Dermatologist and skin care specialist based in Orlando, Florida. This information is not intended as a substitute for the medical advice or treatment of a dermatologist or other physician.
The results from your patch testing showed a positive reaction (contact allergy) to Methylchloroisothiazoline/Methylisothiazolinone. Your immune system reacts with its defense mechanisms with each exposure of Methylchloroisothiazoline/ Methylisothiazolinone to your skin. It is unknown why certain individuals develop allergic sensitivities. In some it may take repeat exposures over long periods of time before an allergy develops. Once you have become sensitized (allergic) your immune system always "remembers" and you will be Methylchloroisothiazoline/Methylisothiazolinone sensitive. If you currently have eczema this chemical may be the cause but other factors may play a role as well. The information below will help you avoid this allergen.
This chemical mix is used as preservative found in cosmetics, shampoos and skin care products. It also has several uses in industry.
Where is chemical found?
Latex paint emulsions
Metal working fluids
Slim control agent in paper mills
Water cooling paints
Hints on avoiding chemical:
Choose products listed only on your personalized contact allergen database, which has been provided to you. Products listed on your contact allergen resource database will be free of Methylchloroisothiazolinone/Methylisothiazolinone and safe to use.
Please be aware that if your spouse or significant other uses topical skin care products that contain this chemical skin-to-skin transfer may occur to you.
It may take 2 to 3 weeks of avoiding exposure before improvement of your eruption begins.
Other names you may see Methylchlorosothiazolone/methylisothiazolone listed as:
Euxyl K 100
Fennosan IT 21
Mitco CC 32 L
Possible occupational Exposures:
Hairdressers and Cosmetologists