so for a couple years now I've had these little bumps that cover only the tops of my arms and the tops of my legs. They feel raised only slightly and some are skin colored and some are kinda red. But the spots they cover I could probably count 10 per square inch. They're the size of pinheads some a little bit bigger. They're extremely visible due to how many there is and I'm tired of trying to just hide them. But they're everywhere on my legs and arms except the bottoms. Some on my chest but not as much. Any idea what it could be?