I was on the same boat 4 years ago.
My skin was so irritated that skin rash would develop idopathically over my body and
my face was filled with acnes.
Now, my acnes and skin rash are completely gone after taking 20,000 iu/ day vitamin D for a year.
Plus, I changed my diet by eliminating all kind of sugars, keeping the intake proportion of protein to veggie & fruit in 1:3
Stop using prednisolone as it will weaken our immune system.
To defend ourself aginst acnes, we need to strengthen our immune cells.
Take a look of the link: www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/