Puss in 10 weeks old chest

Fa

My wife felt some redness on my sons chest and when she touches it she felt a lump. She quickly took him to ped and he checked and said it is something with some insect bit. He also squeeze some puss out of it. N oral medicine just some skin cleaning meds.

It is not painful as baby did not cry at the time but the lump kind of hardness is still there.

Did anyone has any idea what it could be as there is no insect in my home.