I posted a month or so ago about the same thing and the various tests I had taken and planned on taking.  (Not sure where that post is, because I can't seem to find it now.)   The special biopsy showed everything as negative.  The three vials of blood work showed everything as negative.   Complete testing with an allergist came back negative.  No allergies whatsoever.   At this point, even though I have met up with almost 50 dermatologists at the conference, no one knows what this is.  All their suppositions came back negative.   It is now suggested that it is either a drug reaction or a bug reaction.  The drug reaction is ruled out.  I have no bed bugs, fleas, don't garden, don't camp, and no pets in my home.  So, to me, the bug reaction doesn't seem correct.   Still looking for answers.  The rash is in its disappearing stage.  Unfortunately, if the pattern continues ... it will rear its ugly head again in May.