If it is ringworm, clear nail polish works too!! Just paint all around it and make sure it is covered with nail polish. When the nail polish dries it seals and sufficates the ringworm! My son got it from a dog that he was playing with down the road a bit. They forgot to mention the dog had it! We did the nail polish thing and when it was dry, covered it with a bandaid. Just dont use the nail polish on anything else after that!! lol.. But My DH and myself ended up with it and the nail polish took care of it. But just ake sure that is what it is, covering a lingering spider bite wouldnt be good.
Good luck!!
Good luck!!