Ear piecing lump

[Faygs1191]

My daughters had her ears pierced for 13 weeks but I changed them to a pair of silver hoops and now I've noticed this lump behind one of her ears. I'm not even sure what it is... do I need to see a doctor?

It looks like a spot with a white head. It will probably disappear in a day or two.

It does look like a spot but that lumps been there a few days already, wondering if the white head is puss.