My daughter has a 6 month old tea cup Yorkie. One day while playing he either scratched or barely knicked me with his claws or teeth; Long story short I felt what I thought was welt marks through my shirt and two days later it was a red rash with bumps all over it only hurt when I rubbed or scratched the area; now a month later it is still on my right back shoulder blade but it's a dark black area with the same bumps. What could it be? All this happened about a month ago.