Possible ringworm?

Hello all. I am new to the cat site and am hoping you will be able to provide some help. Last night, I noticed a dime sized bald spot on the back of my cat, Mister's, ear/neck area. The spot does not seem to be inflamed or irritated, and I didn't see any sort of scaling or rings. He let me touch the area around the spot no problem, so I don't believe he's in pain. Eating, play, and litterbox habits are all normal, and I haven't noticed him scratching the area any more than usual.

 I know I have to bring him to the vet, but his doctor is out until the Monday after Thanksgiving. In the event it is ringworm, I have ordered some colloidal silver from Amazon which I intend to mix with coconut oil as a topical ointment for him. He does have a previously discovered allergy of some sort that causes him to slightly overgroom his tummy, but that's about it. 

Any help/advice you guys could give would be so appreciated. Thank you much in advance. 

Yes, looks like ringworm to me.  If you have a black light, you can see if it lights up, although it doesn't always 

I'm not sure what you've ordered from Amazon is going to do the trick.  Generic Lamisil should work just fine as ONE of the treatments (but not all)    Here, maybe this thread will be helpful to you:  http://www.thecatsite.com/t/210789/6-things-i-learned-from-our-ringworm-plague-book-length  It's long, but the very first post gives you all the info you really need.