Isothiazolinone Mix Allergy

A few years ago I thought I was having typical seasonal allergies as I get every spring. This time it was different. My poor eyelids were inflamed, swollen, red, the surrounding from brow to under-eye skin was getting dryer as I battled with what the new issue was.  After a couple days of my eyes feeling so sore and sticky, I made an appointment with the dermatologist. He gave me a sample of Protopic to treat the eye soreness while we did a skin allergy test. The ointment BURNED. I had to take it off immediately. I was afraid to use anything on my face at this point, not knowing what the culprit was. 

Few days later, the skin patch test revealed I was allergic to Isothiazolinone Mix Allergy. 

Isothiazolinone mix includes the compounds 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one. They are used together as a preservative in cosmetics and commercial household products such as shampoos, cleaners and washing materials. It also has wide industrial uses. Isothiazolinone mix is more commonly known as the preservative product with the commercial name Kathon. Alternative names: Kathon®, Kathon CG®, Kathon 886®, Methylchloroisothiazolinone (MCI), Acticide, Algucid, Amerstat 250, Benzisothiazolinone (BIT), Caswell # 572A, Euxyl K 100, Fennosan IT 21, Grotan, Grotan TK2, Isothiazolinone (Kathon), Kordek,, Methylisothiazolinone (MIT or MI), Mergal K7, Metatin GT, Mitco CC 32 L, Microcare, Neolone, Optiphen MIT, OriStar MIT, ProClin, SPX, Zonen MT.

This is a harsh preservative and biocide causing allergic reactions on people all over the world! Everything from swollen eyes, dry, bleeding skin, itchy patches to hands full of blisters. It's painful! 

I live in California, most of the pages online I have found most helpful, common side effects as others have been from the UK. There is a lot of information available. You truly do have to read labels. I have a predominantly eye area sensitivity but others get it all over their bodies.


My gosh, I am so happy that you got tested! Can you imagine trying to figure out this allergy on your own? SMH. I'm so sorry to here you had to go through such a painful experience (and on your eyes)... that couldn't have been easy. I haven't had to deal with that around my eyes veyr much, but when my skin gets red, inflamed and itchy I love Emily Skin Soothers for Red, Hot, Angry Skin.

I'm glad you found my blog! Thank you, thank you for sharing this information. It sounds like this mix of chemicals is pretty widespread. It's crazy how many alternate names exist for chemicals, by the way... that shouldn't even be legal!