An abscess is a simple collection of necrotic tissue in a liquefied status; most often infected (with purulent material-pus). Apart from the local symptoms of pain, swelling, redness and limitations of movements due to the location, systemic symptoms like fever are not uncommon.
The best treatment for any abscess or collection of pus is to drain the same with a liberal incision with dependent drainage. Once an abscess reaches the stage of collection of purulent material in liquefied status it is seldom possible to treat with antibiotics or by any other means.