Hi D.
My kids got ringworm pretty regularly at a home daycare we were at once (no longer!). Anyway - my kids got ringworm so bad that they had to be on oral meds for 6-8 weeks. If it gets in the hair - they can lose their hair, so I'd get it checked right away. If they lose their hair, it can take weeks to grow back, and they may lose it in patches.
BTW - the meds are terrible tasting - so get them flavored at the pharmacy - we did, and my kids who normally LOVE to take meds (I know - they are weird!) HATED to take this stuff (Griseofulvin if I remember correctly)....but after months of trying cream to get rid of ringworm, just to have it come back - all 3 of my kids were put on the oral medicine. What a pain!
Good luck!
T.
Mom of 3 - ages 7, 5, 4