Husband has itchy rash (blister)looking on hands, feet, face&and some on torso. One day fever only, already had chickenpox.?

Chickenpox. A "blistering" rash in that many areas in an adult is most likely to be chickenpox. The leans will be the size of a kitchen match on a pale pink base surmounted by clear blister with an indentation (umbilication) at the top. The blisters turn cloudy and then collapse into scabbed lesions. A past history of chickenpox is not always accurate. I recommend a dr. Confirm the diagnosis promptly.
Rash. Serious rashes are usually caused by allergic reactions, disorders of the immune system, or by poisonous byproducts of an infection. Blisters in these disorders are usually caused when the proteins that connect layers of skin are attacked. Because the proteins holding them together aren't working, the layers of skin come apart, and fluid fills the space between them, thus forming the blister.