My cat has strange skin lesions, but it's not ringworm. What is it?

Hello. Without an actual hands on diagnosis, it is difficult to tell exactly what this is, but it does resemble a condition call eosinophilic plaques. If this is what you are dealing with, the condition is frequently associated with underlying allergic disease & tend to respond very quickly to glucocorticoids. The allergies can be to fleas, food, something in the environment & even other insect hypersensitivities like to mosquitoes. The cornerstone to therapy is trying to identify & manage the underlying cause(s). If this is done, the prognosis is excellent for a very manageable condition. Thanks for using Petco Pet Education Center, formerly Petcoach.