What could be wrong with this poor cat? she has bald patches and sores.?

A neighbour called me as she thought she had found my missing cat, it wasn't my cat but I took her home to feed and look after as she was in a bad way. She managed to escape, but came tentatively back to mine today. She is in my outhouse at the moment with a sofa a bed, food water and a heater. I am taking her to vet tomorrow. She is skin and bone and her long fur is all matted and stuck together. she has quite a bit of hair loss, and some sores on her exposed skin. I tweezered a copule of tics out of her skin also. I know she has fleas and I know I'm going to have to blitz the outhouse when shes sorted, hence why im not bringing her in house. From my description what do u think could be wrong? she was frightened at first but is incredibly loving to me and wants to sit on my lap, I've been very affectionate to her, but kind of worried after reading about ringworm and the like that I could catch something from her. As I said im going to vet tomorrow, but anyone have any advice for me or know what she might have? I've put a pic on animal search uk, and am going to get her scanned for a chip tomorrow, and if no joy then put posters up around my local area. I hope she has been missing for a long time as opposed to having a cruel owner.