If you have signs of ringworm so long you need to go for doctor again. They can give for you oral tablets too if it is ringworm.
It also good be not ringworm. I know infections from pets also cause problem that is looking similar. The difference is they need to use other medications. Also too, ringworm can look like other problems. If it is at his waist band, he may have a sensitivity reaction in contacting a button or his belt. I just looked and the condition is called granuloma annulare. It can come and go. I hope this can be made to go away.