question: Hi, My son is 18 months old and cutting 4 molars at one time 3 have surfaced but one had a bubble that formed on his gum, the Dr. called it an eruption cyst he has had a fever of 101.0 F. and is very very fussy, he will not take any pain medicine, he does not want to eat, but he will still nurse. We checked the spot and now it is filled with whitish yellow puss, do we need to be concerned now?