OK, we can't write your answers for you, but we can show you where to find them.
If you google "treatable skin conditions" the results will go a long way to answering your question.
Do you have a text book for your course? If not, go to the college library and borrow one. If you don't know where to start in terms of books ask your tutor.
Please don't think I'm being obstreperous by not answering your question outright, but you're never going to learn if you don't exercise a little resourcefulness.