My calico cat, Snickers, has always had a problem somewhat with dandruff (she has thyroid issues so she is predisposed to having dry skin). However lately it has escalated to the point where she has hot spots from her tail to as far up her back as she can reach. One of them got infected so she has been on an antibiotic for the last week, and topical sprays, and we buzzed her fur on her back so I can keep an eye on the rest of the irritated spots and use a special shampoo to help soothe them. The vet said he thinks she has allergies but I can't imagine what it would be that would bring it on so suddenly. She has been on the same food and the same litter since she was a kitten. I'm going to start her on a healthy skin and coat food tomorrow but is there anything else I can do to relieve the itching and irritation she has? I know she's miserable and I hate not being able to do anything to stop it right away :(

If the vet suggested allergies, she is probably thinking inhalant (seasonal) allegries. Antibacterial or drying solutions are the best you can do since they interfere with the infection cycle and itchiness.
There is an oral cortisone type drug we have given dogs in the past for a short period to help with the uncomfortatble itchiness (mostly so they dont self mutalate the area) but I'm not sure if there is a suitable medication and dosage for cats. Might be a good question for the vet.

Thank you for the info! Snickers has another follow up this Thursday so I will definitely ask. The vet suggested benadryl, but for some reason the tablet (maybe the taste?) makes her foam at the mouth horribly and sometimes she will throw it back up as a result. This isn't a cat who has never taken a pill, either. She has a daily one for her thyroid. So I am guessing I should try the liquid form or a different type of tablet. I will definitely bring this up with my vet. The shampoo does seem to be helping as far as healing the hotspots, but she still rolls her back a lot so I know she's still itching :( Hopefully we will find a solution soon, even if it's cortisone injections, I'm to the point where I just want her to feel better!