What Causes Soreness Along With Itching In Anal Region?

My mom has had for about a year off and on a real redness both sore and also itchy around her anus area on both sides of her cheeks. She has been to the doctor but the problem persists and she doesn t know what to do as the problem is still there and it is unbearable at times, either with pain or itching. Was wondering if she should be sent to a dermatologist to help with diagnosing the problem or what? Thanks! p.s. another problem that my mom has is that she injured her leg on the front shin down towards her foot and it sort of healed up after going to the doctor a lot, but she has had to have a boot put on nearly weekly for a long time now and it heals up but not entirely and then gets rather red around the area. She has diabetes, or at least she used to, the doctor is no longer sure that she still does, but I am worried about it not really healing like it should and always having to go to the doctor for a boot every week but no true healing! HELP! Thanks again.