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. An abscess can be located anywhere in the body and can present challenging clinical situations when located inside the abdomen, flank, chest, brain and tissues deeper to the facia etc. These abscesses have to be evaluated on the basis of the presenting signs and symptoms and also ustilising the advanced modalities of imaging. In this lesson we shall deal with abscess involving the subcutaneous plane and perhaps those just deeper to it. When an abscess tends to localise, its liquid content will enable you to elicit the signs of fluctuation. An abscess, which is fluctuating, will open by itself through a small sinus and will lead to chronic non-healing sinus. So it is very important that all abscesses are opened with liberal incisions. For this reason in certain areas cruciate incisions are made and in certain other areas incision and counter incision are also made.(Although the presence of fluctuation gives a clue that the abscess is ready for incision and drainage it is advisable not to wait for this sign particularly in areas like breast, parotid and the perirectal area. Sometimes, early intervention and drainage can protect tissues from further damage). In most situations the nature of infection and the organisms can be detected by clinical reasoning and appropriate empiric broad spectrum antibiotic therapy can be started just before or after the incision and drainage while awaiting specific culture reports. Suitable modifications on the antibiotic regimen can then be made on the basis of the report. In certain locations like face, it is occasionally possible to manage small abscesses by needle aspiration and antibiotic therapy to help avoid scars in the face. But, this has to be carefully planned and evaluated and utilised only in circumstances where it is possible to handle by this method. If the pus is thick and not possible to aspirate well, prompt incision and drainage should be undertaken. Occasionally, to promote adequate drainage particularly from deep pockets, corrugated rubber drains are placed and gauze packing is utilised to prevent premature closure before all the pus is drained and for healing to take place from the bottom. Each abscess has to be dealt with according to its location, extent, depth and presence or absence of vital tissues like blood vessels and nerves in the area. Diagnosis of abscess may sometimes be difficult and particularly where normal blood vessels are expected, difficulties in differentiating between pulsatile hematoma, abscess, aneurysm etc may occur. In such circumstances, if by clinical diagnostic methods, one is unable to come to a conclusion, a preliminary 22 gauge or 23 gauge needle aspiration of the swelling may be considered before incision and drainage is done. If the aspirate is purulent, incision and drainage can be performed. On the other hand if it is blood, needle is withdrawn, some pressure is applied for a few minutes and then further testing is carried out before specific treatment is given. When choosing anaesthesia the following factors have to be kept in mind: Children Deep seated abscess Abscess in relation to bony injuries Most frequently seen subcutaneous abscesses, particularly located in the extremities and trunk particularly in adults may be reasonably handled under local anaesthesia using 1% xylocaine. Whenever GA is used: It is better that surgery is carried out with adequate O.T. facility. It is very important to make sure that patient is in empty stomach before general anaesthesia is induced. In dealing with the elderly and those with cardiac and other problems, appropriate monitoring may be required. Use of ethyl chloride spray to incise and drain an abscess by freezing the surface is not recommended for the following reasons: This is a highly inflammable material The anaesthesia is inadequate It cannot be used in locations particularly face etc. Risk of damage due to frost bite (eyes). It may be used to a very limited extent in fluctuating superficial abscesses where a quick procedure is possible.