One is to treat it right away and take care of the problem, such as extracting it, which would then allow the pus to drain out of the socket. The other approach is to provide antibiotics to reduce
and then treat the affected tooth. Either way is fine and depends on the situation and judgement of the dentist. If your dentist isn't too concerned, I would say it would be okay to wait. If it worsens, they can drain it for you.