Hello...
I had a light brown spot form on my inner arm a few years ago. In recent months, it has changed shape and colour, with an itchy red/sometimes bleeding little spot appearing on it.
I went to a dermatologist who treated it with liquid nitrogen. A blister formed and it appeared to be clearing up over a 6 week period. Albeit without the brown colouring, a little red itchy spot/sometimes bleeding is now forming again.

Any thoughts on what this might be? I am a 45yo female, and have lived in sunny climates for many years.
Thanks
Scotty Ski

Time to go back to the doctor. There is a chance it could be skin cancer, but we can't diagnose via the internet.