Bit by something on a camping trip baseball size reddish rash with bruising Pics included Any Idea?

Hello we're in central Illinois and went camping over the weekend my friend first noticed the bite on Saturday which looked like a mosquito bite. It was normal skin color and about the size of a peanut M & M. It was itchy. On Sunday the bump was gone and in its place was a large reddish rash with bruising. It is not painful to the touch and does not appear to have gotten bigger than on sunday although the bruising has gotten slightly more purplish in color there is no signs of puss or any type of fever. As soon as this is posted i will add a photo bucket link with pictures. We were attacked by mosquitos and chiggers that weekend and its deer tick territory out there...we also have brown recluses in that area i've nver seen a bite like that. What do you think it was? Shes trying to avoid a hospital ill if she can....what do you think?