weird sores

our cat has weird bumps on the back of her neck that turn into scabs that then turn into round open sores - no scratches or anything, just open wounds. we've had her blood work done and she's been tested for allergies but nothing turns up abnormal. Any suggestions?

I think more information might be necessary. What kind of tests did you have done? Did you try switching her to an allergy food (duck or venison) ? Has she been tested/treated for ringworm? Fleas?

I agree with Sicy, it sounds a whole lot like ringworm, or possibly an allergic reaction to fleas. My mom's cat Max is allergic to fleas and if even one or two bites him, he gets big sores. I would definately talk to your vet about that...

Does she wear a collar? If so, could she be allergic to the material in the collar?