It would be helpful if you could mention some more details regarding where does the swelling come and when ? is it associated to a tooth ? Does it look like a pimple ? It could be appearing due to infection spreading from the tooth to the gums as a result of infection involving the nerves of the tooth. There is nothing to worry about, however a clinical checkup and an xray is a must to diagnose the issue. If the nerves are involved and there is infection, it will heal with a simple root canal procedure.

Hie. Ok.. if possible share pics.. as it’s a 2 year old problem.. need to know the proper history..