I've had a red mark on my torso for quite some time now and I noticed that I have another one on my left arm but it isn't as dark or as big as the one on my torso.
I also have a few little red freckle looking marks on my arms as well. They are very tiny. Probably not visible if you weren't looking for them.
Below is a picture of the red mark on my torso. It is about 2mm in size. If I press it hard it turns light pink then goes back to red. It doesn't hurt and is slightly raised (I can feel it if I touch it lightly).
The flash made the mark look two different colors but it is completely red in person.
The marks kind of look like broken blood vessels.