Why does my 3 year old have a small bald spot?

Several possibles: There are a number of reasons for 3 year olds to get bald spots. They can just be yanking at hair in the area and pulled it out there. Can be from a skin irritation or infection, like a fungal infection of the scalp (tinea capitis.) Can also be from too much traction on area if hair is pulled back a lot. Also can be condition where areas of hair just fall out for no apparent reason (alopecia areata)