My dog has a small spot (looks like a skeeter bite) on her back. She doesn’t seem to be bothered by it. However, it seems to have gotten bigger from a small mosquito bite to about the width of my thumb. It looks like there is a scab in the middle of the spot. She does suffer from dry skin, and I noticed a month ago that exactly where this spot is had been bleeding. I used a styptic stick (sp?) on it to stop the bleeding. What could this be?