A furuncle (also known as a boil) is when a hair follicle becomes infected causing a pus-filled lump. It is usually caused by bacteria known as staphylococcus aureus which is found on many people’s skin or in their noses. It tends to cause no harm, although it can cause an infection such as a furuncle if it gets under the skin. Furuncles look like a red lump that is painful and initially quite hard but over the course of about 4-7 days gets softer as the amount of pus inside increases. You may see it progress to have a white or yellow head on the lump. The skin around the furuncle may also become red and sore. In a few cases, multiple furuncles can occur in the same area, known as a carbuncle. The pus may come out of the furuncle on its own or be reabsorbed by the body. Once the pus is released it can take around 4-5 days for the furuncle to heal and may leave a scar. The advice is not to try and burst the furuncle yourself. Furuncles are quite common especially in teenagers and young adults and most small furuncles go away on their own without the need for any treatment. They can be painful especially as the amount of pus in the furuncle increases. They are usually found in places on the body that are warm and moist or where there’s rubbing (either on other skin or clothes) that occurs in the area such as armpits, groin, bum, neck, or face. This happens because warm and moist conditions are ideal for bacteria and any friction can cause breaks in the skin allowing the bacteria to get in. Furuncles are more common in teenagers or young adult males, those with a lowered immune system, diabetic patients, people who are overweight or who already have a skin problem that may make them itch or scratch their skin.
The bacteria from the furuncle can spread to other people so it is important to try not to touch the area but if you do then wash your hands thoroughly before and after. Do not share clothes or towels and avoid swimming whilst you have a furuncle.
Soak a flannel in hot water (but not boiling - make sure it is not hot enough that it could burn your skin) and apply it to the area around 4 times a day. This can help draw the pus to the skin's surface and help speed up the healing process. It should also help relieve some of the pain. You can also take over-the-counter pain relievers such as paracetamol. Keep the area clean and wash your towels and clothes regularly.
You should see your doctor if it is not improving after a week, if it is a large furuncle or you have multiple, if the furuncle is on your face, if it is a child who has a furuncle or you have a lowered immune system or suffer from diabetes. See your doctor urgently or call NHS 111 if you have a furuncle and feel unwell (such as a fever) or if the redness around the furuncle is rapidly increasing or tracking your body.
The doctor will ask you about your symptoms, your medical history, and any relevant family medical history. They will then examine the area and discuss with you the next course of action. For small furuncles it is likely the doctor will ask you to keep the area clean and monitor it as it heals on its own. For large furuncles, the doctor may make a small incision and drain the pus out. They will then clean the area and pop over a dressing in order to keep the area clean whilst it heals. In a few cases, your doctor may prescribe medications such as antibiotics.