I started wearing a helmet 2 years ago. Since that time I have noticed that the normally clear skin on my scalp, I'm pretty much bald, has become somewhat blotchy. It's only noticeable under a strong florescent light. I also wear synthetic skull caps which serve to keep my helmet clean and to keep me from getting weird tan lines on my head.
Since noticing this, I've begun to wear cotton bandanas under my helmet instead of the skull caps. I notice an immediate increase in comfort. The bandana feels so much more comfortable against my skin. I've only been doing this for a few days so it is too early to tell if my skin has been getting irritated by being against the plastic helmet and cap.
Anyone ever notice irritation from their helmet?
BTW, I'm one of those people who cannot wear a new shirt until it has been washed.
Granted, I may have just a little more hair, I get irritation under the chin strap. It's usually after a shave if the helmet strap is clean and it can be even without a shave if the strap is dirty. It may be the salt from your sweat irritating the skin along with the constant contact (or rubbing in my case) with the skullcap. A cotton headwrap may be more absorbant and therefore more comfortable. Washing out your helmet and skullcaps more often may help.