I took her to the vet and we ruled out allergy to food because I switched foods after this started happening, but no change. She does have dandruff, but the Vet says only on the part of her back where cats have a hard time cleaning themselves. I guess this has been a VERY bad year for allergies, in humans as well as cats...so you're probably right. It must be allergies. Do you think an air purifier might be of any benefit?