Boil, also called furuncles, are painful, red lumps filled with pus on the skin above infected hair follicles. When boils appear in a group, they are called a carbuncle.
Boils are painful as they get bigger, before bursting on their own after some days or weeks.
The most common places for boils to appear are on the face, neck, armpits, shoulders and buttocks. When a boil forms on the eyelid, it is called a stye.
Causes of boils
Most boils are caused by a germ (staphylococcal bacteria). This germ enters the body through tiny nicks or cuts in the skin or can travel down the hair to the follicle.
Some health problems make people more susceptible to skin infections, including:
Problems with the immune system.
Exposure to harsh chemicals that irritate the skin.
Symptoms of boils
A boil starts as a hard, red, painful swelling usually less than 4 cm in size. Over the next few days, the swelling becomes softer, larger and more painful. Soon a pocket of pus forms on the top of the boil (pointing).
These are the signs of a severe infection:
The skin around the boil becomes infected. It turns red, painful, warm and increasingly swollen.
More boils may appear around the original one.
You develop a raised temperature.
Nearby lymph nodes (glands) may become swollen.
When to seek medical care
You have a high temperature.
The skin around the boil turns red or red streaks appear.
The pain becomes severe.
The boil does not drain pus.
A second boil appears.
You have a heart murmur, diabetes or any problem with your immune system or use immune suppressing medications (for example corticosteroids or chemotherapy) and you develop a boil.
Boils usually do not need immediate emergency attention. If you are in poor health and you develop high temperature and chills along with the infection, you should seek urgent medical advice.
Examinations and tests
Your doctor can make the diagnosis with a physical examination. Many parts of your body may be affected by this infection on your skin, so you may be asked questions about or have an examination of other parts of your body.
Boils treatment - self-care at home
Apply warm compresses and soak the boil in warm water. This will decrease the pain and help draw the pus to the surface. Once the boil comes to a head, it will burst with repeated soakings. This usually occurs within 10 days of its appearance. You can make a warm compress by soaking a flannel in warm water and squeezing out the excess moisture.
When the boil starts draining, wash it regularly with an antibacterial soap until all the pus is gone. Apply a medicated ointment and a large plaster or gauze. Do not use a waterproof plaster that excludes all air. Continue to wash the infected area - two to three times a day - and use warm compresses until the wound heals.
Do not pop the boil with a needle. This usually results in making the infection worse.
If the boil is severe but no pus is released, your doctor may lance the boil to allow drainage of the pus. If there are concerns about the seriousness of the infection, additional blood tests may be performed. Your GP may prescribe antibiotics if the infection is severe. If the boil is drained, a culture may be done to determine the type of bacteria causing the infection and to assess if an appropriate antibiotic was given.
Next steps - follow-up
Whether the boil is drained at home or is lanced by a doctor, you will need to clean the infected area two to three times a day until the wound is healed. Apply an antibiotic ointment after washing and cover with a plaster or gauze. If the area turns red or looks as if it is getting infected again, seek medical advice.
Help prevent boils by following these guidelines:
Carefully wash clothes, bed linen and towels of any family member who is infected with boils.
Clean and treat all minor skin wounds.
Practise good personal hygiene.
Follow a healthy lifestyle.
Most boils will disappear with simple home treatment.