Over a month ago, I had what I thought was a bug bite on one finger , with swelling and itching in other fingers. Over several days, the small blisters I started with grew, looking more like a poison ivy reaction for a couple of days, but then the blisters grew larger until they merged into one large blister. The affected area itched and was tender. The blister eventually went down and the itching went away, but my hand is still red everywhere it was affected and tingles at random times throughout the day. Any ideas what is going on?