Im 55 yrs old have a chronic skin rash (ie small red bumps not assoc with hair follicles, acne, etc.) that does not itch and first started on my chest. I noticed it several years ago and figured it was one of my many allergies (i m real fair skinned, blonde, blue eyes, etc.). I suffer from depression and am actively being treated for this mental health problem. The rash worsened about 6 months ago and became more prevalent moving closer to my neck and now covers the top of my back and back of my neck and I now find it on my arms and legs. Each little red dot is a real small bump below the skin. Are there blood tests my doctor can order to help me get to the bottom of this hive like , expanding skin rash? What could be causing this?