My 84 Year Old Mother Has An Inflamed Rash Through

My 84 year old mother has an inflamed rash through her hair on her forehead really red and itchy and appears on one side of her face by the outside and behind her left ear. A rash circle around her breast and all over her back and torso . Red broken down skin on the back of her thighs and purple red skin on her buttocks. She has always had sensitive skin but this has been going on for 4 months a course of steroids temporarily helped. She was put on anastrozole for breast cancer so they changed that last week to another similar drug nothing seems to be helping poor Mum she is miserable