Skin abscess: symptoms, causes, drainage and when to get help

An abscess is a collection of pus that builds up in a pocket of tissue as the body tries to wall off an infection. When it forms in or under the skin it is called a skin abscess. The NHS says there are different types and that they can appear anywhere on the body.

Boils are a closely related problem. The NHS describes a boil as a hard, painful lump filled with pus, often starting as an itchy or tender spot, and says a group of boils forming together is called a carbuncle. In practice the distinction matters less than the signs of spreading infection and whether the lump needs draining.

Abscesses can also occur in other places such as the teeth, around the anus or deep inside the body. This guide covers skin abscesses; the principles of drainage and warning signs overlap, but deeper or dental abscesses are assessed differently.

The NHS says a skin abscess is a lump or swelling on the skin that contains pus. It will often be round and feel painful and warm, and the middle of the lump may feel soft when touched. Pus may leak from the abscess and you may have a high temperature.

On white skin an abscess will often appear red. The NHS notes that the colour may be harder to see on brown and black skin, so swelling, warmth and pain are important signs to rely on rather than redness alone.

The NHS explains that skin abscesses are usually caused by an infection. It is normal to have bacteria on your skin without it causing an infection, but bacteria can sometimes get into the skin, for example through a cut or along a hair follicle, and cause pus to form.

You may be more likely to get skin abscesses if you smoke, are living with obesity, have diabetes, are between 15 and 40 years old, or have a skin condition or inflammation such as eczema. For boils, the NHS adds a long-term condition that affects the immune system, such as diabetes or HIV, taking medicines such as steroids, malnutrition, and close contact with someone who has boils.

The NHS advises seeing a GP if you have a lump that is getting bigger, a lump anywhere on the body that lasts more than 2 weeks, a lump that is hard and does not move, a lump or swelling in the breast, or a lump when you have a weakened immune system or a long-term condition such as diabetes.

• Ask for an urgent GP appointment or get help from NHS 111 if the lump is painful, red or hot, or you feel hot, cold or shivery.

• Seek the same urgent advice if swelling or redness is spreading away from the lump, remembering that redness may be harder to see on brown or black skin.

• For a boil, the NHS also lists a boil on the face, skin around the boil that feels hot, painful and swollen, and a weakened immune system, for example from steroids or diabetes, as reasons to get urgent advice.

Treatment depends on the type of abscess. The NHS says the abscess may need to be drained to get rid of the pus. This usually involves a small operation to make a cut in the skin so the pus can drain, and you may be given a local anaesthetic so you do not feel it. You may also be given antibiotics if the abscess is infected.

For boils, the NHS says a GP can check whether you need treatment, which may be a small procedure to drain the boil or antibiotics. Pain relief with paracetamol or ibuprofen is suggested for discomfort.

Because of the risk of pushing infection deeper or spreading it, the NHS advises not to pick, squeeze or pierce a boil. A healthcare professional should drain a lump that needs it.

For boils, which share the same principles, the NHS suggests holding a clean cloth soaked in warm water against the lump for 10 minutes, 4 times a day. If pus comes out, clean the area with antibacterial soap and cover it with a dressing or gauze until it heals.

• Bathe or shower every day and wash your hands regularly.

• Wash towels and bedding at least once a week at a high temperature.

• Do not share towels with other people until the boil has gone.

• Do not go to a swimming pool or gym until it has gone, because you could pass the infection on.

• If you are very overweight and have boils between folds of skin, losing weight may help.

Repeated abscesses deserve a proper look. The NHS advises seeing a GP if you keep getting boils or have a group of boils. A GP can look for contributing factors such as diabetes, skin conditions, or medicines such as steroids, which the NHS lists among the things that make boils more likely. Describe where the lumps appear and how often, as this helps the GP decide on the next step.

Managing the conditions that make abscesses more likely, such as stopping smoking, controlling blood sugar and treating eczema, is part of prevention.

Most skin abscesses are assessed and drained in primary care or at an urgent treatment centre, with NHS 111 available for guidance. Larger, deeper or recurrent abscesses, or those in people with significant health problems, may need hospital surgical review.

Private minor surgery or dermatology services offer another route for drainage or for investigating recurrent lumps, usually with shorter waiting times. The clinical principles are the same, and any service should explain aftercare and who to contact if redness or fever develops.