Hello, Welcome to health care magic. From your description, I would like to rule out a few possibilities like blistering disorders( bullous pemphigoid), bullous lichen planus, insect bite reactions, Id eruptions and contact dermatitis.Scabies in adults in general do not blister. I would advise you to repeat a skin biopsy for histopathological examination and a special test called immunofluorescence. Please do the test before starting on prednisolone or other steroids as this can alter the biopsy picture. Hope this helps you.