After bathtime my husband found this on my son’s (17 months) back. His sister has been in a biting phase but that’s something we totally would have noticed so we’re thinking it’s not that. It’s also like a perfect circle so we’re thinking ringworm 😩 do I just put ointment on it or do I need to take him to the doctors? If it is ringworm we have NO idea how he got that either. We play outside and have a dog but we’re a pretty clean family and it’s on his back, which I don’t think it a major sweat spot. Any advice is welcome. Thank you!!