and welcome to the forum!
Abscesses are generally painful...so, if it turns out to be that, make sure you ask for a pain relief med.
And - on that topic, be careful about what you may get, There's one pain med that's very often prescribed nowadays which has caused no end of misery for cats - a fact that seems to escape most Vets. The drug is called Metacam
...it's an anti-inflammatory chemical which, in cats, kills kidney cells. You can read all about it here http://www.metacamkills.com
There are alternatives...an easy alternative is a liquid which is dropped into the corner of the mouth (not swallowed) and is absorbed through the buccal tissue.
A second medication caution: if the problem is an infection, an antibiotic will certainly be prescribed. Again, there is one to be avoided if at all possible. It's called Convenia
...get it? "convenient", because it's a long-acting injection...no pilling required, etc.
Well, Convenia has been far from convenient for many cats and, IMO, would be something to avoid, especially as there are safer alternatives. Here's one reputable Veterinarian's take on Convenia http://www.catinfo.org/?link=convenia
People here at Pets.ca
have had their own horror stories to share as well http://www.pets.ca/forum/showthread....light=convenia
Hope this helps - keep us updated!