skin reaction to a epinephrine injection

Question
my 5 month old Yorkie had a epinephrine injection so she wouldn't react to her rabies injection however she reacted to the sight where they gave her the epinephrine. she could hardly walk,lay down or anything without crying the first day. The next day she was fine although I noticed a bald spot at the sight of the injection, a couple of days later.  Now her hair is starting to grow back in but it is a different color than the rest of her body. Her body is starting to turn steel blue but the spot is black with a brownish orange color and the area that it is in, it should be growing back steel blue.  Could this be a reaction to the shot or do you think it might be the true color that she is going to turn? I hope that I'm not bothering you with a silly question. I just think my yorkie is going to look funny with a big brownish orange spot on her back with the steel blue   Thank You for your time!    Donna

Answer
Epinephrine is a very potent vasoconstrictor and that means that the blood vessels in tha area of the skin were so constricted that there was not good blood supply to the skin.  That may account for the reaction.  Sometimes, however, the rabies vaccine can cause ths type of reaction, too. I would receomend using the rabioes vaccine in the muscle rather than under the skin and using Benadryl rather than epinephrine to prevent a reaction.