Hi mialove1 ! Welcome to the forum!
I strongly suspect that what you're dealing with is a type of allergic reaction commonly seen in cats.
Sometimes it's a reaction to a food ingredient, sometimes (as Reg mentioned) it's associated with using plastic dishes (glass/stoneware/stainless steel are preferred), and sometimes it's the result of a brush with some transient allergen.
If you haven't made any food changes/additions before the time these spots first appeared, then investigating a food allergy would not seem needed.
Cats' immune systems are particularly watchful when it comes to the skin.
This is NOT something you can treat successfully 'at home'. Mia will need to see a competent feline Vet (most general practice Vets do poorly with feline health issues...particularly when things get finicky).
Here's a plain-language coverage of what's most likely going on (from a reliable site!): http://www.marvistavet.com/html/eosi...granuloma.html
If you read carefully through there, you'll understand that this condition, once started, will go on and on in a never-ending circle until the immune system is told to put the brakes on by using the steroid, thereby giving the itchy area time to heal up....and stop itching.
If you have a 'general practice' Vet, this might be an opportunity to find a cat-only practice. Post back if you need help with that.