Can someone please help identify these strange cuts on my skin.

[AnthonyBan]

I have had these appear seemingly out of the blue with no memory of any type of injury. They are painless and begin as what seems to be a small red scratch and by the next day have small openings along a line. Under a magnifying glass it looks like a hole in my skin as if the top layer of skin was cut away. They do not itch or bleed and can only find them after visual inspection. I have had 3 appear several weeks apart on my calves and forearm. They heal and scab in around 10 days. I can provide pictures, please help. Thank you