I had suffered the same skin allergy for almost 21 years now. It's an on and off relation. Now they are getting aggressive . They itch. My previous doctor said , those appear because of tension and sun exposure . But now a days I don't go out still they pop up, and they leave a scar ( pic has small bubbles which are allergy and if they grow big ,they leave scars like in the pic) .Appears only on arms and legs and at the start there was a pattern, they appeared along the veins but now as I said they are getting aggressive, became clusters. They are very irritating and eating my self confidence . Please some one help!