Cat dermatitis: Is DepoMedrol the only answer?

Question
Hi...

My 5 yr. old shorthaired 'tuxedo' cat was diagnosed about 6 mos. ago by our vet as having allergic dermatitis.  He has since had 3 shots of DepoMedrol, but the excessive licking and hair loss on his belly has not stopped.  It seems to slow down a few weeks after the shot, but not for long.

Aside from wondering if there are any other options, I also wish I had a clearer understanding of my cat's condition.  I am not inspired with confidence in our small town vet, as he persisted in giving me vague explanations like, "It's just that he's got an allergy, maybe allergic to himself or something..."  

I don't doubt that the injections work, it's just that I can't believe my cat is comfortable if he is that itchy all the time...perhaps you can set my mind at ease?  Thanks in advance!

Answer
There are many causes of itching in the cat. Allergies to environmental allergens occur commonly.  Food allergies, ringworm and external parasites can also cause itching.  DepoMedrol gives a low level of steroid, which calms the skin down in some allergic cats, but it is not the whole answer to the problem if there are not allergies.  Some cats will respond to an antihistamine called chlorpheniramine when the steroid does not help.  Dietary supplements containing Omega3 fatty acids help to prevent the skin from being so itchy.

If you are concerned that your cat may have some other type of skin disease, then allergy testing, fungal cultures, skin biopsy, and diet trials are all things that can be done to diagnose your cat's problem.