A skin abscess, also referred to as a boil, is a lump that develops under or inside the skin's surface. Typically, this lump is filled with pus or transparent fluid. It is often caused by a bacterial infection.
Written by Dr. Julia Cheong, MBChB, BSc (Biochemistry) on 30.3.2021
Medically Reviewed by Dr. K on 31 March 2021
Table of contents
- Skin Abscess
- What is a skin abscess?
- Where can a skin abscess occur?
- What are the signs and symptoms of a skin abscess?
- Who is affected?
- How is a skin abscess treated?
- How do I prepare for the procedure?
- What will happen during the procedure?
- How long will it take?
- What are the risks and complications?
- Managing after the surgery
- Can I prevent getting further abscesses?
- Follow-up after the surgery
Skin abscesses (also known as boils) are quite common in the general population and may require antibiotics or a small operation in order to be treated.
What is a skin abscess?
An abscess is a cavity containing a collection of pus, usually caused by a bacterial infection. A skin (cutaneous) abscess is one that forms just under the surface of the skin. It can be very painful and make you feel very unwell. Sometimes, the abscess can burst, leaky pus, and can have an unpleasant smell. It is important that you go see a doctor if ever you feel unwell with an abscess or if it is very painful and does not go away after a few days.
Where can a skin abscess occur?
Skin abscesses can occur anywhere on the body. Abscesses that form in between the buttocks or around your anus (perianal area) are the most common and often require quick intervention.
What are the signs and symptoms of a skin abscess?
You may develop only a few or all of the symptoms below:
- A swelling just under the surface of the skin. You might sometimes see pus forming under the skin. The pus can look white, yellow, or even green. There might be an unpleasant smell if the abscess has burst;
- Pain, redness, swelling, and heat around the abscess;
- Feeling generally tired or unwell.
Who is affected?
Anyone can get an abscess and most occur for no apparent reasons. For example, abscesses can occur as a result of a blocked sweat gland or a hair trapped under the skin. However, if you have diabetes, you are more at risk of developing recurrent abscesses.
How is a skin abscess treated?
The main way to treat an abscess is to drain the pus away by making a small cut (incision) in the skin. This procedure is also known as incision and drain. The surgeon who is in charge of your care will perform this procedure. This can be done in a ‘special procedures’ room or in an operating theatre.
If the skin surrounding the abscess is infected (cellulitis), your doctor might also prescribe some antibiotics to help treat the infection.
How do I prepare for the procedure?
- You may need to have some routine blood tests. The team looking after you will arrange for these to be completed.
- If you are taking anticoagulants (blood-thinning medication) you may be required to stop taking them prior to the procedure. You should continue to take your regular medication as usual; however, patients taking warfarin will need to have this stopped by their referring doctor. If you have stopped drinking prior to the procedure you should take your medication with sips of water.
- You may have a light meal six hours before the procedure and continue to drink clear fluids up until two hours before the procedure. Clear fluids = water, clear squash/apple juice, black tea or black coffee, clear herbal teas.
What will happen during the procedure?
A nurse will take your details and attach a monitor so she can record your blood pressure, pulse, etc. The surgeon will explain the procedure to you before asking you to sign the consent form.
The procedure is normally done under anaesthetic. Depending on the size of the abscess, you might:
- Be awake for the drainage but the area around the abscess will be numbed with anaesthetic to prevent pain (local anaesthetic); or
- Be asleep for the procedure (general anaesthetic)
The local anaesthetic may sting briefly; you should then only feel touch and pressure in the area where the surgeon is working.
The surgeon will make a cut in the abscess to allow the pus to completely drain out. A sample of the pus might be sent to the lab for further analysis. Once the pus is drained, the wound will be washed with an antiseptic solution or with saline. The wound will be left open so that any pus that collects again can drain. If the abscess is particularly big, your surgeon might pack some antiseptic dressing in the wound to reduce the risk of infection and help the rest of the pus to drain properly. A dressing will be applied and the wound should heal in two to three weeks. The wound is likely to leave a scar.
You will be taken to a recovery area or ward on a bed or a trolley. Nursing staff will monitor your blood pressure, pulse, temperature, wound site, etc. to make sure that there are no problems. You will generally stay in bed for a few hours until you have recovered.
Informed consent will be obtained prior to the procedure. Staff will explain all the risks, benefits, and alternatives before asking you to sign a consent form. If you are unsure about any aspect of the treatment proposed, please speak to a member of staff.
How long will it take?
Every patient’s situation is different, and it is not always easy to predict how difficult the procedure will be. The procedure may take about 30-45 minutes.
What are the risks and complications?
Incision and drainage of a skin abscess is normally a safe procedure but, as with any medical treatment, there are some risks and complications that may arise after the intervention:
- Bleeding can sometimes occur although in the majority of cases this is self-limiting and only very occasionally will further treatment be required;
- Damage to adjacent structures under the skin is a rare complication;
- Once the abscess is drained, antibiotics are rarely needed; however, if the skin around the wound starts to become red, swollen, or hot, you may need antibiotics
- As the wound heals, it may leave a visible scar on the skin
- If you have had an abscess around your anus, there is an increased chance of developing an anal fistula. An anal fistula is a tract or tunnel that forms between the anal canal (where faeces pass) and the skin around the anus. Despite drainage of the anal abscess, this is not enough for the fistula to go away. In this situation, you are likely to require another surgery to prevent further abscesses. Symptoms of anal fistula can include a smelly discharge coming from the skin opening, persistent pain, swelling, discomfort, and irritation around the anus. If you experience any of these symptoms persistently after your surgery you should see your family doctor.
Despite these possible complications, the procedure is normally very safe, and will almost certainly result in a general improvement in your medical condition.
Managing after the surgery
Most people can go home on the same day as their surgery unless there is a special indication for you to stay in. For example, depending on the situation, your doctor might want to keep you overnight to give you some antibiotics through a vein in your arm to help treat the infection.
You will be given painkillers if needed, but once the abscess is drained, most people notice that the pain improves significantly.
In the first few days following your surgery, the wound dressings will need to be changed daily. Once the wound is healing, the dressings will need less frequent changes.
If you have had a perianal abscess drained, you might be advised to consume a high-fiber diet. This is to prevent constipation, pain, and disruption of the wound site as it heals.
Can I prevent getting further abscesses?
Although most abscesses occur for no apparent reasons, adopting some simple, healthy lifestyle measures can help reduce the risk of further abscesses:
- Eat a healthy balanced diet;
- Good personal hygiene;
- Keep your skin clean and healthy;
- Avoid smoking;
- Control your blood sugar levels if you have diabetes, as this will reduce the chances of developing an abscess
Follow-up after the surgery
Most abscesses heal very well and do not require any follow-up in the clinic. However, your doctor can arrange an appointment if they feel they need to see you again.
Referenced on 30.3.2021
- Percutaneous Drainage patient leaflet (with permission from Nicky Perkins, Radiology sister, DCH)