Cat with blisters

One of our "outside" cats (we care for about nine cats outside, as well as our three "indoor" cats), who we call "MomCat," because she had kittens a few months back and still dotes over them, has blisters/pimples/sores on her neck and head, and I am wondering what I can do to help her with these. She is pretty gentle, so I expect that she wouldn't mind if I were to put some antiseptic, assuming that would heal them, on her sores. I would really appreciate any assistance, because I love this kitty, she's a beauty.

It's very possible these sores are ringworm, although impossible to tell from where i sit. Head and neck are common for ringworm, showing as roundish bald spots with raised reddish or grayish welts/sores. Not dangerous but will spread especially if untreated. Anti-fungal cream on the spots twice a day will speed recovery.

However, it may be something else. Can you take her to a vet?

The spots are not bald, actually, I noticed them when I was stroking her. I can take her to the vet, but I was keen to know if there was any way that I could treat her on my own. Are there any other symptoms of ringworm ?