Shingles blisters usually scab over in 7-10 days and disappear completely in two to four weeks. In most healthy people, the blisters leave no scars, and the pain and itching go away after a few weeks or months.But people with weakened immune systems may develop shingles blisters that do not heal in a timely manner.mall blisters that appear only on the lips or around the mouth may be cold sores, sometimes called fever blisters. They're not shingles, but are instead caused by the herpes simplex virus. Itchy blisters that appear after hiking, gardening, or spending time outdoors could be a reaction to poison ivy, oak, or sumac.