What is making me itch?

I'm a 33 year old female that decided to get more serious about my skin care after noticing a few forehead wrinkles. I've tried two different sensitive-skin daily moisturizers with SPF, and both caused a very mild rash with noticeable itching around my jawline.

I also use a mineral makeup that seems to make me itch slightly. If I wear a cream foundation underneath the mineral powder I don't seem to get any reaction, since I think the foundation is providing a barrier. However, a light dusting of the powder mineral makeup alone has me itching after a few hours.

I can't find a common ingredient. I'm trying to be better about using a daily sunblock, but the waste of money has got me discouraged. Same for the mineral makeup. It looks *fantastic* but I'm always itchy by the end of the night.

Any suggestions are very appreciated :)

[Caryopteris]

It sounds like the powder is too drying for you.  Revlon Photoready foundation is good for me.  I am having trouble giving up powder to set my makeup, but I am cutting back due to dry skin.  The moisturizer I am most impressed with is Avalon Organics Vitamin C sun-aging defense Moisture Plus Lotion.  It really softens skin texture appearance for me.