Hi and thanks for using the forum.
You should try some warm soaks to the area- or sitting in a warm bath for a while to see if it helps. Betamethasone is a cortico-steroid cream which can help with the inflammation and the swelling. If you do not see an improvement in a day or so, or if you see that the abscess is getting worse, then you should get it checked out by your doctor. Sometimes, antibiotics are needed to treat the abscess and sometimes they need to be drained. I hope this helps. Good luck.