Allergy in cats

Question
My cat began itching and scratching a lot and she began to lose hair.  I took her to the vet and he said she had an allergy either to fleas or food.  We put her on Revolution for any fleas and I changed her food to Natural Balance (Allergy formula).  He gave her a cortisone shot.  The shot cleared it up and the hair grew back and then a month later it started again.  He said he can't keep giving her the shots and I can't afford allergy testing.  Can I use hydrocortisone cream or something else on her to relieve the itching?  If I can stop the itch, she will stop scratching and the hair will grow back.  She is almost 10 years old and has been extremely healthy all her life.  She is strictly an indoor cat and has never been outside. Most of her problem is up around her head and ears. Thank you for your help.

Answer
Cats are very tolerant to steroid injections.  On rare occasions, some cats will develop diabetes because of too much cortisone. If the shots help, that is the simplest and cheapest way of handling cat allergies.  There is new treatment for allergies that many of us are using in cats.  It is called cyclosporine (ATOPICA).  We use a 25mg capsule daily for 3 weeks and then we use it twice weekly if possible.  It is more expensive and it is hard to pill a cat. Other than vomiting in some cats after giving the medication, there are no other side effects. If vomiting is a problem, then we give metoclopramide liquid (REGLAN) 30 minutes before pilling the cat.

The problems with hydrocortisone cremes are many.  First a cat will lick it off right away.  Second, it is worse for the cat's skin than the shots. tT can cause atrophy and thinning of the skin where it is applied for a long time.  Third, you only spot treat with a crame.  With a shot or cyclosporine, it will get to everywhere in the skin that is reacting.