Ringworm is a fungus, it is not a worm. It is called ringworm because the lesions that it causes are circular and raised up around the ring. While ringworm is not dangerous, it can make you MISERABLY itchy! You need to take your nephew to a doctor or to a dermatologist who can prescribe an antifungal medication to get rid of the ringworm. It would also be a good idea for the person who owns the dog to take the dog to the vet so it can be treated as well. It makes dogs as itchy as it makes people, and the dog can scratch himself to the point where he creates open sores that can get infected if the fungus is not treated.
Ghilly
Ringworm can be contagious. I strongly you suggest you make an appt for your nephew to see his doctor for an exam.