cat hair loss

Question
I have a sweet female cat (rescue) that is approx. 3 years old.  We rescued her and her brother at the same time.  She has always been afraid of everything!  Took me two years before she would come up to me and let me pet her, and I was the only one she would let pet her.  We also have two other male cats, one of which is her brother. She is constantly hiding because at times the older male cat has been extremely mean to her.  She will not take up for herself, but instead hides.  Very sad.  Hides during day and comes out at night. A couple of weeks ago she came out of hiding and I was shocked at her condition!  She was losing all her hair on the back of her body, and around her neck she had small scabs.  Since she came up to me I was able to pick her up (normally I can't catch her) I have isolated her now. My thought is that the larger male cat attacked her and due to stress her hair is coming out.  All the cats are inside cats.  I spend time with her daily and she seems so glad to see me.  She will let me pet her and seems to enjoy it as long as I don't make any quick moves, then she's under the bed immediately! She eats well, uses the litter box great, but her hair looks terrible.  Her hair is still beautiful around her upper body, the scabs around her neck are almost gone, but her lower body still looks horrible!  She is such a sweet loving baby, but also acts almost like a feral cat when it comes to people.  I am the only one that she will allow to pet her and if I make any quick moves she's gone!  Her brother, on the other hand, is Mr Personality!! Hope you can help.  Also she is an inside cat, never been outside.  She has been isolated for about 3 weeks.

Answer
With hair loss and scabs, I would think of either some type of allergy or ringworm.  You should get her to a vet that can examine her and make that determination.  Sometimes, all we have to do for allergies is to give a long acting steroid shot.  For ringworm, it is a little more involved, with bathing and oral medication.