I have one or two eruptions that are very itchy that look like misquito bites but they are not . They erupt one or two at a time in the area of my waistline only. They are extremely itchy. After a week or so they heal up and leave a mark. I though maybe I had shingles but these are not ever sore and painful, only very itchy. After they heal up, I find more in another place near my waistlin. What are they?