cat hair loss

Question
Hi, I have a 1 year old male cat who has been neutered and had his shots.  he is an outdoors cat.  he has been having trouble for some time with scabbing and hair loss around his back legs.  the vet suggested an allergy, so we have him on a hypo-allergenic food.  we use a spot-on treatment for both fleas and round worms, so we know he is clear of those, but he still seems to be developing some new patcehs of baldness.  the latest one has appeared around his genital area, and the edges of the the patch are quite hard.  he has the same sort of hard lumps under his left armpit.  we are trying to limit his access to other foodstuffs from other people in the street, but we really don't know what to try.  The sore bald patch on his back leg is getting better, but the hardness of the other areas does not seem to be clearing up, even when the hair grows back - which it has done a couple of times now.  The vet keeps giving him steroid shots, but obviously i would like that to not be a permanent thing.  any suggestions would be much appreciated!

Answer
If they haven't checked for ringworm I would suggest having them do that.  Ringworm can appear as circular lesions with hair loss and scaly skin.  They can be self resolving, which can explain why it is getting better then popping up somewhere else.  If its not ringworm, and it is in fact allergies you should speak to your vet about having him tested for allergies.  He may have an allergy to grass, or fungus, in which case putting him on a hypo-allergenic food isn't' going to help.  If they test for allergies then they can also develop a serum so he can have injections periodically to build up his immunity to anything he is allergic to.  It is a long process and can be expensive but in the long run is much better for the health of your cat as steroid injections can cause liver damage over time.  I hope he gets better.

Amanda