What Causes The Outbreak Of Blisters On Feet, Arms And Buttocks?

I am 47 years old and suffer with MS. But the past 6 months have been horrible! I started getting blisterlike places on my feet then my arms and buttocks. I have noticed that the areas itch horribly before the blisters appear. Then I get sick at my stomach extreme fatigue and some fever. I have no energy while this is going on. I have seen several different doctors all with different ideas and treatments. I feel better while I am on antibiotics but soon after finishing them it starts over. I have had a round of steroids and have been given 5 different antibiotics. Nobody seems to have any idea what is wrong and I am getting very down over feeling like this and getting no answers. Now I am being sent to a dermatologist. I don t think this is a skin issue, it is coming from inside my body. The first blister was treated as a spider bite and I feared that it had become systemic and was spreading throughout my body. But that ddn t seem to be a concern. I have had blood tests done and my wbc is always elevated and my glucose low. I don t know where to go or what to do and I am really tired of all of this!!