I would definitely see a dermatologist if it continues. Could be just contact dermatitis

See a doctor. It could be a lot of things, but could be just stress. Find out!

Have it checked I had what I thought was a scab on my head I'm always loosing my balance I thought I hit my head Dr sent me to dermatologists and it turned out to be cancer so best to get it checked out

As one or two of you have noticed I wouldn’t discount the possibility of stress as a causal source of some skin issues, particularly if you are taking prescription drugs for PD. The best relief for me has been to listen to plenty of good music with the volume up! I don’t think the type of music matters just as long as you like it. Leonard Cohen, the Eagles, Handel all work for me the warning on the tin is that you make sure your partner likes it too! Good luck, Bryan

Any open areas on skin you cannot explain need to be seen by a physician. Especially if he is diabetic. Unexplainable sores can get worse very fast and are nothing to wait on.