My Mother Has Crippling Rheumatoid Arthritis All Over Her Body

My mother has crippling rheumatoid arthritis all over her body on her left hand she has what looks like a burn n the palm of her hand n on two I of her fingers, she's had mrsa on that hand before. I've been doctoring it n keeping it clean but it just does not want to heal she's not running any fever with it,she eats good but it itches quite a bit finite after I cleaned it it started to burn n throb could she have Mesa again n if not what can I do to heal it?