Last night, I found myself scratching the back of my right hand. I checked (not easy, since I was in a room without any light save that of the computer) and it was covered with bumps. These were only red where I'd actually scratched, and once I knew they existed, they were less itchy. I have contact dermatitis, but these looked nothing like my normal hives. I took a Zyrtec, but I don't know if it did anything.
In a couple of hours, they were smaller and some had developed tiny shiny points - still skin colored.
We tried to figure out causes. I'd eaten nothing unusual, unless you count a Jonagold apple. It might have been the wool, as I have been doing a lot of knitting, but the way I work, the back of my right hand never comes in contact with the wool, and my left hand was rash-free. I'd made meatballs for dinner, and had worn vinyl gloves while dealing with the ground beef, but I wore them on both hands, and they were from the same box.
It was slightly annoying, so I put some lidacaine ointment on it, and decided that this was not the night to wear my brace - I sleep with a "cock-up" brace on my right hand for the carpal tunnel problems, and it does cover that part of my hand. It covers, in fact, everything, front and back, from the middle of the palm to halfway to my elbow. Also, I'd last worn it at 7AM that morning.
They seemed unchanged when I woke up and I seriously considered calling one of my dermatologists, but shortly afterwards, they shrank even more. Right now, it's down to slightly itchy raised, shiny red dot, and I suspect it will be gone by the end of the day.
I know mysterious rashes happen.