She's probably lonely and has developed this nervous habit of licking her fur off. Have you considered adopting a kitten? Then at least she'd have a "buddy" while you're away. We have 3 cats and they are just like human siblings - they fight and then end up sleeping nose-to-nose on the sofa! They always have each other when we're away.
and in her case, it was related to being hyperthyroid. Is she on the skinny side? Jumpy?
Just before Christmas my cat started pulling all of his fur out, we couldn't understand why, i tried a few creams but they didn't help, finally after the Christmas holidays we took him to the vets. They told us that he was allergic to a flea bite and they gave him an anti inflammitary (sp?) injection, which stopped his skin getting irritated, the vet also told us that it's a very common thing. You might want to look into that. Good luck!!
I had a cat that lost some hair at the top of her head. I don't know if she was licking it off, or if it was some kind of irritation. The vet didn't notice anything abnormal, and the skin itself didn't look irritated. But I took her home and started treating it myself with neosporin. The hair grew back and we never had another problem.
Is she by chance a siamese? They tend to be more emotional than other cats. So if she is it could definitely be a stress-related thing. My cat is half siamese...
My cat Dizzy has been overgrooming for the past year, since my now husband moved in. (He licks his front legs, stomach, and the bottom of his back feet, most recently). And Dizzy loves my husband, so I think it was more the change in the environment: the extra furniture, etc. So it might be the change in the cat tree in your cat's case...my vet said that the tiniest change in their environment can trigger such behavior. Or she might just miss you alot when you are out of town. Do you have a good pet sitter or friend to spend time with her while you are gone?
I, too, just put my cat on Venison and Green Pea to rule out any allergy component, although I am pretty sure his is completely behavioral, as he is a pretty sensitive cat anyways. Feliway may or may not work....I couldn't tell any difference with mine, but it certainly might be worth a shot with yours.
Good luck, and I hope you find something that works!
I forgot to mention - she has a litter mate - Samson, and they've never been separated. So, I don't think she's completely lonely - although my travel may have something to do with it. She doesn't have fleas as they never go outside and I've checked her several times as did the doctor and no fleas. I hope she likes the Venison and Green Pea but neither her nor Samson will eat the Duck and Pea and they both have to eat it as I can't feed them separately. I do have a friend check in on them when I am gone, but she only comes by once or twice a week. I have her stop by if I'm gone 3 days or more. I hate to ask her to do it more often.
Hopefully the itch meds and the new food will help. She is thin - however - not much thinner than Samson. They are 1/2 Siamese and 1/2 Maine Coon. Very pretty kitties and VERY CHATTY!