WHAT ARE THESE?

I have had one of these spots on my left index finger for as long as I can remember. I noticed one came up on my upper left arm a few years ago, but now there are two or three more in the same area. I also have one on my right ring finger, and a few on my legs around the knee area. Also have some newer ones on my right shoulder/upper arm area as well. I first thought they had come from the sun but started searching online and became rather concerned reading forums about other people with similar problems.

The picture shows the three on my upper left arm. One of which is very splotchy around the actual red spot..

Please, any help would be greatly appreciated!