After the wound shed scab, it was red, as if there was blood stasis. It didn't come out after taking a hot bath. What should I do? Can leave scar??
According to your description of the symptoms and the pictures uploaded, considering the formation of spots after local trauma and the symptoms of congestion at the spots after bathing, in this case, the local blood vessels can be contracted by local cold compress to gradually recover a little smaller. Whether to leave scars depends on the damage at that time. If they have been damaged below the dermis, they may leave scars.
From the picture, it may not be completely recovered. If the scab has fallen off, or this situation occurs, it may be that this part was not cleaned at that time and there are some pollutants. It can be observed for a few days to see that it can gradually absorb and recover.
In this case, do not touch water for the time being, and there should be no obvious scar, because the scratch is still relatively shallow. You can apply some alcohol disinfection locally to avoid scratching and picking with your hands. This scab will be on the line when it recovers slowly.