I Had An Extensive And Painful Rash Which Was Eventually

I had an extensive and painful rash which was eventually diagnosed as shingles about a month ago.
For the last 7 days I was virtually symptom free; the rashes had blistered, crusted, dried, and disappeared. No further pain. My energy had come back as well. On Friday evening, I went to bed with a sore throat. On Saturday morning I awoke to a severely sore left side to my tongue, causing me to talk as if with a lisp. I also discovered that on my chin, a rash had re-appeared. I was worried, but thought it was coincidental. The rash spread throughout the day, onto the bottom of my face, and the backs of my ears.
I coated it with Calagel (which I had used successfully with the shingles), and covered the areas last night. I awoke several times through the night with prickling pains across the rash areas and further. This morning the rash was spreading down primarily the left side of my neck, all the way around my mouth, and onto the tip and bottom of my nose. I also developed a small rash on my forehead, in the shape of a horizontal line. The pain sent me to an urgent care where I was diagnosed with acute dermatitis and given KEFLEX for the areas that had been rubbed or crusted open, and a cortisone shot to reduce the swelling. I was planning to call a dermatologist tomorrow to look into these very close problems. I rarely have skin issues. I am 51 years old and am a 2 time breast cancer survivor. My problems are normally bronchitis type complications from colds. Do you think I should schedule with the dermatologist to get to the bottom of this? I really can't recall using anything new that could have caused such an acute reaction.