My daughter has a round rash like thing on her side. and it super itchy. could it be ring worm? can i treat it over the counter?

Must verify the rash: Itchy spots can be from many causes such as: eczema, hives, viral infections, other infections (like ringworm fungus), medication causes, heat rashes, etc... That means a rash that persists or is worrisome in appearance should be examined. In toddlers, an itchy round area is commonly eczema or less often ringworm. One's pediatrician can look at it. Sometimes an online video exam will suffice.