Your rash could be caused by methylisothiazolinone

Your rash could be caused by methylisothiazolinone

Do you have eczema, contact dermatitis, rash or other skin irritation and don’t know what’s causing it? There could be several reasons and you’ve probably considered a lot of them by now. There’s one trigger that you might not have heard of. It’s called methylisothiazolinone.

Read on to find out what it is and what it does.

Some skin flare-ups may be triggered or made worse by different types of irritants to the skin. Your skin might react to allergies, some types of fabric, changes in temperature and even stress.

I had atopic eczema when I was a child and still have some rash in my fingers. I’ve also suffered occasional itching, swelling and red rash in the skin around my eyes until I learned what causes it. The problem was that I used shampoos that contained methylisothiazolinone and/or methylchloroisothiazolinone. I changed the shampoo, have been careful not to use shampoo that contains them anymore, the skin around my eyes has healed and I’ve not had any problems since.

What is methylisothiazolinone?

Methylisothiazolinone(MI) and methylchloroisothiazolinone (MCI) are both very commonly used preservatives. They contain anti-bacterial properties and are used to increase the shelf life of a product. You’ll find that a product often contains either MI or MI and MCI together. The mixture of MI and MCI might also be labelled as Kathon CG®.

Methylisothiazolinone is a surprisingly common allergen

Methylisothiazolinone is one of the most common causes of allergic contact dermatitis. It is believed that over 10 % of people with allergic contact dermatitis are allergic to MI and MCI.

The number of people allergic to methylisothiazolinone seems to be rising rapidly. The preservative was actually named the Allergen of the Year by the American Contact Dermatitis Society in 2013.

You can notice that you’re allergic to methylisothiazolinone literally overnight. You become sensitized to it over time. That’s one of the reasons you might find it difficult to pinpoint the reason for your rash:

You haven’t changed anything.

You might have used the same shampoo for years and then all of a sudden you get a rash in your head, face or elsewhere in your body. It is very difficult to tell what’s causing the rash.

It took me a while to realize that it was the shampoo causing the rash to the skin around my eyes. By then I had already changed my mascara, eye cream and eye shadows. It was by accident that I read an article about methylisothiazolinone and realized most of my shampoos contained this preservative. There was one particularly nasty shampoo that always made the rash in my fingers really itchy – I noticed that it contains both MI and MCI.

Is it just the shampoos that contain methylisothiazolinone?

Nope, it’s everywhere. You might not have heard of it, but when you start digging you’ll find that it’s everywhere. You’ll find methylisothiazolinone in:

  • Shampoos, conditioners and other hair products
  • Hand washes
  • Washing-up liquids
  • Laundry detergent
  • Makeup
  • Cleansers
  • Sun creams
  • Skin care products
  • Baby wipes
  • Hair dyes
  • Air fresheners
  • House paints

Buying shampoo for example is really difficult – it doesn’t matter if it’s a cheap or an expensive brand, at least to me it seems that around 98 % of them contain methylisothiazolinone and/or methylchloroisothiazolinone.

I think it’s crazy that it can be found in baby wipes and even if you use a laundry detergent that claims to be ”sensitive”, it still probably contains MI or MCI.

methylisothiazolinone products

How do you know if you are allergic to methylisothiazolinone?

Most people that have this allergy have rash at least in their hands or face. If you suspect you could be allergic to methylisothiazolinone, you should:

Go through the above mentioned products in your house and see if they contain MI or MCI. Stop using products that contain methylisothiazolinone and see if your skin gets better.

If you want to be sure about the allergy you can speak with your dermatologist about having a patch test.

Why is methylisothiazolinone even allowed?

The use of methylisothiazolinone has increased dramatically in the past few years. Some years ago all the attention was focused on the use of parabens. The manufacturers started to use more methylisothiazolinone instead of the parabens with the results that we can see today.

The European Commission have this summer banned the use of MI and MCI in leave-on body products. However, the manufacturers are still able to use it in rinse-off products and this is considered safe in the limited levels.

Until these allergies get more media coverage the companies will be unwilling to come up with alternative safer preservatives.

Is there anything we can do?

I don’t know about you but the older I get the more and more I want to focus on using natural products when it comes to skin care, food and health in general. I would love to get rid of all these manufactured chemicals. I think we should find ways to make our own products, from natural ingredients.

I’m already often using coconut oil for skin care and would really love to learn more about other ways how to use natural products. If you have a tip on how I could make my own shampoo for example I would love to hear about it! 🙂




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