Ringworm?

[Tasha3207]

I just got my 4 month home from daycare and I noticed this on his arm. He has been happy all day. 2 days ago he got shots for his check up...not sure if it's just a reaction? The one side of the circle where the edge is darker does feel raised a tiny bit.

[GAtherton Administrator Fungal Infection Trust]

Ringworm (which is an infection by a fungus called Tinea) would most likely appear slowly and tend to form a ring of redness surrounding much paler skin, sometimes scaley in appearance - see webmd.com/skin-problems-and... for examples. I don't see that in your picture.

If at all concerned or if it doesn;t clear up in a day or two see your doctor.