What Causes Outbreak Of Red Blotchy Rash Followed By Fever?

My mom has had a rash that is red blotchy an it brakes out when running a fever an when it looks like its healing it turns into a brown scar. Her doc doc gave her cream for it an it don t help. Her vitamin d was low. She s had this going on for 5months now. The rash spreads an it kinda goes away then come back