After years of living with perioral dermatitis, I have finally worked out what has been causing my sensitive skin - bismuth oxychloride in my mineral make-up.
I'm 33 years old and about 5 years ago I started getting red, scaly, itchy spots on my cheeks and chin. I initially went down the medical route (prescribed antibiotic creams etc) which helped briefly, but then just made my skin worse in the long run. About a year ago I discovered that SLS that I used in face wash and aqueous cream (routinely prescribed in the UK for eczema, dry skin) was an irritant, so stopped using and switched to SLS, paraben etc- products. This undoubtedly helped clear my skin. However at the same time I also switched to using mineral make-up in the hope that it would suit my sensitive skin better. Despite not using any other products on my skin (just plain SLS-free cleanser and baby oil to moisturise), my skin has just got worse over the last few months, which naturally coincided with me using more mineral make-up to cover it up. I've tried a tonne of the other remedies suggested on this site, but got no long-term benefit. To cut a long story short, I researched mineral make-up some more and found that bismuth oxychloride is a known irritant (i'm surprised it's not mentioned more on this site). I stopped using the makeup a week ago and my skin is 95% better, I'm amazed - for the first time in years when I run my fingers over my cheeks they are smooth and soft and the blemishes have nearly almost gone.
I've ordered a sample of a pure mineral make-up from a small company in the UK (that doesn't use bismuth, talc etc), but at this rate I won't be needing any cover up! I thought it was worth contributing my story in the hope that bismuth may be responsible for anyone else's sensitive skin. Note it's contained in lots of make-up powders, blushes etc (its what gives makeup its 'glow'). Best wishes everyone and thanks for a great site!