I Have What Looks Like Bad Acne On My Tight

I have what looks like bad acne on my tight thigh. Now I notice white spots under th e skin. I broke out with wgat looked different on my right arm & then what looked different on my right ankle. First my dr made sure ut was not shingles. I was prescribed predisone which has helped the arm & ankle. I am taking the predisone for the second time which seems to b hrlping my thigh. I do have pictures if the breakout I can forward.