fur loss/overgrooming?

I have noticed a small area on my Persian's back which looks like she has lost a lot of fur which is now growing back. It is not lumpy or itchy, red. She gets regular flea treatment with frontline. Does this sound like she has been grooming herself excessively and am I right in thinking this is a sign of stress? I can't think of any recent stressors. I do have another cat who she bulies a bit and is not too keen on but he has been with me for about 18 months. Help appreciated.

I wish I could give you some simple help. With cats and hairloss, it could be so many things. Usually loss of hair on the back is due to a flea allergy. One thing you might consider is if she has a flea allergy, all it takes is one bite to trigger it. Even with frontline, they usually have to bite in order to die.
If she goes outside, it could be a type of mange, mites, or a skin infection. In order to rule any of those out, she would have to see a vet and have them do a skin scraping.
Stress, illness, or compulsive disorders can also cause some over grooming. If you see her licking the hair off, then it's very possible that it's one of these things. Vets who deal with this sort of thing, can tell weather the hair is just thinning, or being broken by licking. If it's her doing it, then the 2 options are usually pinpointing the reason behind it, and trying to fix it, or a variety of medication to help them deal with it.

Sandie - thanks for your suggestions. I don't think it is a flea allergy as she had that when we got her and her back was very red and lumpy but I will get her to the vet and see what he says.

I don't know if this is useful or not, but my mother had a cat that used frontline and the cat had a bald spot on her back. They changed from frontline to something else and the hair started to grow back. I had never heard of that before her cat, and the vet really didnt know what was going on either. Just a thought

Could possibly be frontline i suppose but i've been using it on her for years and it's been ok. i think the fur is starting to grow back and suspect that she probably feels a bit bored as i've had to disappear upstairs and work whilst she wants to play!It's too cold here in the uk for her to go out so she's maybe just bored. i've been lavishing attention on her and the bald spot is not gettting any worse. the skin is not broken and there are no lumps or scabs so it doesn't seem to be a skin infection or allergy. she is due for boosters soon so i'll let the vet have a look at it. thanks for responding.

My mom had used frontline for years too and never had a problem, thats why I was kind of interested in if you thought that could be a cause..Ive found that cats are as mysterious as kids, why they do some things and why some things happen. lol