A mucous cyst often can be left alone; it usually will rupture spontaneously. Opening the top of the sac with a sterile needle will help it go away. If the cyst returns, it may need to be removed.
To prevent infection and damage to the tissue, opening the sac should NOT be performed at home by the parents. This should be performed by your health care provider. Oral surgeons and some dentists can easily remove the sacs if they continue to be uncomfortable.
There are usually no complications.
If it becomes uncomfortable, have the cyst examined by your health care provider during a routine examination.
Maheu-Robert LF, Andrian E, Grenier D. Overview of complications secondary to tongue and lip piercings. J Can Dent Assoc. 2007; 73(4):327-331.