Dry Shampoo and Scalp Irritation

I'm hoping someone can answer some of my questions regarding dry shampoo!
I love dry shampoo for its ability to make my fine hair have texture. I don't so much care about it cleaning up a dirty, oily, scalp since my scalp leans more on the side of dry. I wash my hair every 2-3 days. In between those days I use dry shampoo. At least up until my scalp has been going crazy. It's been drier than ever and not so much itchy but just dry. No flakes. Though, I started getting hairline pimples and a few on my scalp. Which for myself is odd. It's not my shampoo, conditioner, or styling products. I slowly tried each on their own to see if those may be the culprit. Nope! But when I tried my dry shampoo all the above problems returned?! I'm baffled as to what in the dry shampoo would cause these problems? I should mention it's the same dry shampoo I've been using for 1 year. So my questions??:
1. Has anyone else experienced a dry scalp, irritation, or hairline/scalp pimples from using a dry shampoo?
2. I have a dry scalp but love the texture and volume dry shampoo provides-should I be using an alternative product for those results? If so, any suggestions?
3. Powder or Spray? Is there a difference in results for hair type or scalp care?
FYI I've been using Tresseme Dry Shampoo. Help! I need volume and texture in my hair!

I have the same problem as you I realised that it was the dry shampoo for me as well it dry shampoo has so much alcohol in its unreal I don't get why they sell it really because alcohol dry out the scalp. my hairline at the top is red and irritated and its caused dry patches . I would suggest using and organic one. I have thrown mine will get organic one. I wash mine once a week because I dye hair and want to keep colour in for longer lucky I don't get oily scalp till the 5th day of week. also the aerosol can ones because you spray it the pressure may be too harsh for the scalp I suffer from chronic Uticicaria so I got to be careful. So your not alone and in the mean time to help your scalp heal try massaging tea tree oil or vitamin e oil to red areas