I don't know but so I am asking can it be blister disease? I have never seen it just read about it but the way you spoke about the problem sounded like what I have read on it. I really hope it is something simple and not blister disease, it might be worth a consideration, I assume that the pre rescue conditions were bad.? Just I thought. good luck

"The first signs are usually watery blisters on the reptile’s skin. These blisters then burst and transfer the infection into the reptile’s body, leading to septicemia, an infection of the blood which is potentially fatal, as well as infection in the internal organs. In addition, the skin around the initial blister may rot away leaving the body exposed and even more vulnerable to other bacterial and fungal invasions as well as injuries, abrasions and burns. Mites can also spread bacteria to the blisters and in some cases, bacteria can cause abscesses at the site of the blisters which recur as ulcers following the next shed."


http://www.reptileexpert.co.uk/BlisterDisease.html