I have allergic contact dermatitis, confirmed allergies to 4 things diagnosed by patch testing. The bottom line about ACD as opposed to sensitivity is that true ACD is a delayed response as it goes through your immune system. Reactions start anywhere from 2 days to 2 weeks so it’s pretty much impossible to figure it out on your own. If you have real ACD and you have a reaction, it could be an ingredient in something you’ve come into contact with anywhere, anytime for the past two weeks.
I say this to encourage anyone who has persistent problems to get the patch tested! You may be able to find out for yourself a sensitivity that is an instant reaction, but you will never find out a real allergy by trial and error.
For example, one of mine is methylisothiazoline, a common preservative in many products but very common in shampoos and conditioners. But … my hasty reaction is around my eyes, not on my scalp. On my own, I’ve tried to research every product I’ve used on my face. I would never have ended up on MI as a culprit without the patch tests because it wasn’t even in the things I used around my eyes. It is a different matter for ACD to react in different places, regardless of where the actual perpetrator was deployed.
So … don’t want to preach, just hope to help someone. If you have persistent, confusing problems … get the patch tested!
