A skin abscess happens when pus collects in hair follicles, skin tissues, or under the skin. A furuncle, also known as a boil, is a painful infection that forms around a hair follicle and contains pus.
A carbuncle is collection of boils that develop under the skin. When bacteria infect hair follicles, the follicles can swell and turn into boils and carbuncles.
A furuncle starts as a red lump. It may be tender. The lump rapidly fills with pus, and as it grows it may burst.
Furuncles, boils and carbuncles typically affect the thighs, armpits, buttocks, face, and neck.
Individuals with weakened immune systems, adolescents, and young adults are more susceptible to furuncles than younger children or older adults.
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Furuncles and carbuncles: How do they differ?
Furuncles and carbuncles are similar but with some differences.
Furuncles develop rapidly as pink or red bumps. They are often painful. The surrounding skin is typically red, inflamed and tender.
Carbuncles and furuncles are a kind of skin abscess.
The lesions often appear on the neck, breast, face, buttocks or thighs. They occur in places prone to hair, sweat, and friction, and they tend to start in a hair follicle.
The bump fills with pus within a few days, and it grows. The bigger it gets the more painful it becomes.
Furuncles may go away without any intervention, but sometimes they burst and heal without a scar within 2 days to 3 weeks.
They are common among teenagers and young adults, and they affect males more than females. Overcrowded and unhygienic living conditions increase the risk.
A carbuncle is less common than a furuncle, or boil. It is a collection of boils on one site. It is larger than a single boil, measuring up to 4 inches across. A carbuncle usually has one or more openings that drain pus onto the skin.
The most common cause of a carbuncle is a bacterium known as Staphylococcus aureus (S. aureus). The infection may lead to generalized body symptoms, including a fever of 100.4 degrees Fahrenheit or higher, and a general feeling of being unwell, weak, and exhausted.
The infection can spread to other parts of the body, and it can spread to other people too, so that other household members may develop one at the same time.
Carbuncles are most likely on the back, the thighs, or the back of the neck.
They affect males more frequently than females, and especially older men with poor health or a weakened immune system.
Carbuncle infections tend to be deeper and more severe than those caused by furuncle. The risk of scarring is higher, and they take longer to develop and to resolve than furuncles.
S. aureus, also known as staph bacteria, live on the skin and inside the nose and throat.
Usually, the body's immune system keeps them under control, but sometimes they enter the skin through a hair follicle, or through a cut or graze in the skin.
When the skin becomes infected, the immune system responds by sending white blood cells to the affected area to destroy the bacteria. Pus is an accumulation of dead bacteria, dead white blood cells, and dead skin.
The following conditions increase the risk of developing furuncles:
- Diabetes: High blood sugar, or high glucose levels can reduce the immune system's ability to respond to infection
- Medications: Some medications weaken the immune system
- HIV and some other diseases: Certain conditions weaken the immune systems
- Skin conditions: Psoriasis, eczema, and acne increase susceptibility
Often, the normal bacteria in a person's nose or on their skin can lead to an abscess. Sometimes, however, the infection can spread between people when sharing space, materials, or devices, such as clothing and whirlpool footbaths.
Treatment, complications, and prevention
A number of solutions can help to relieve the symptoms of skin abscesses.
Applying a warm face cloth for 10 minutes a few times a day may help speed up the healing process. Heat draws more blood, and so more whites cells, to the affected area and encourages pore dilation and release of pus.
It is important to wash the hands thoroughly after touching the site and to avoid squeezing a furuncle or carbuncle, as this increases the risk of spreading infection.
The doctor may use a sterilized needle to lance the abscess, which means pricking it and draining the pus away.
An abscess can be surgically removed.
This must not be done at home, but by a health care professional with the proper training and equipment. Antibiotics should only be used if recommended by a medical professional.
Complications and prevention
There is a risk of secondary infection, which is when the infection spreads to other parts of the body. Cellulitis is one type of potentially serious secondary infection that can occur.
Ways of preventing boils and carbuncles include:
- Keeping the skin clean by washing it regularly
- Immediately cleansing all skin wounds, cuts, and grazes, however small
Putting a sterile bandage over any cuts to help prevent infection.
Eating a healthy, well-balanced diet and getting regular physical exercise will improve your general health and your immune system, reducing the risk of developing furuncles and carbuncles.
When to see a doctor
A furuncle usually goes away after around 2 weeks without treatment, but if a fever accompanies the abscess, the person should seek medical help.
Hot packs and lancing may be sufficient to resolve them, but if the infection spreads to a deeper layer under the skin, antibiotics may be recommended by a medical professional.
Experts say patients should not try to burst or squeeze furuncles or carbuncles. If the lesion is very painful, if it lasts for more than 2 weeks, or is accompanied by an elevated body temperature, you should see your doctor.