What Is an Abscess?

A skin abscess is a walled-off, bump-like collection of pus that appears either within or just below the surface of the skin. Abscesses are typically caused by a bacterial infection.

They tend to appear on the back, chest, buttocks, and face. Sometimes, they develop in areas where hair is present, such as the armpits and pubic area.

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Furuncles and carbuncles are two similar types of skin abscesses. A furuncle, sometimes called a boil, is caused when a hair follicle becomes infected and creates a small abscess. A carbuncle is defined as multiple pus-draining follicles that combine to create a single infected mass.

Furuncles and carbuncles tend to appear in areas that have been exposed to minor trauma, sweat, or friction (such as beneath a belt or where the skin has been irritated from shaving).

This article explains the symptoms, causes, and treatment options for abscesses. It also points out how to prevent them from developing in the first place.

Abscess Symptoms

An abscess looks like a little bump or a pimple that can grow into an inflamed, fluid-filled cyst. The skin surrounding an abscess is often painful and warm to the touch. In some cases, an abscess can be extremely hard and firm (indurated).

Depending on the cause, the appearance of an abscess may be accompanied by fever, nausea, or swollen lymph nodes (lymphadenopathy).

Causes

Abscesses are most often caused by a bacteria, called Staphylococcus aureus, which normally exists on the skin and inside the nose. It can enter the body through a cut, abrasion, puncture, or even an insect bite. Other factors can increase the risk of S. aureus infection, including:

• A chronic skin condition, such as acne or eczema
• A weakened immune system
• Close contact with an infected person
• Diabetes
• Poor hygiene

A condition called folliculitis can cause an abscess to form within a hair follicle. Infection begins when a hair is trapped beneath the surface and can't break through (a condition commonly referred to as an ingrown hair). Folliculitis can be caused by shaving (particularly in Black people). It is also associated with swimming in an improperly chlorinated pool or hot tub.

Diagnosis

Diagnosis is usually made on appearance alone. While smaller abscesses usually can be treated at home, medical attention should be considered if an abscess:

• Becomes painful
• Develops on the face
• Grows to be more than 2 inches in diameter
• Persists for more than two weeks
• Propagates into more than one
• Recurs after treatment

Treatment

Small abscesses can be treated at home with a warm compress to relieve pain and promote drainage. A larger abscess may need to be drained at the doctor's office to both relieve the pain and treat the infection. Depending on the cause of an abscess, a doctor may consider whether an antibiotic is needed.

Antibiotics are often prescribed to people who have a weakened immune system or are experiencing whole-body symptoms like fever. In such cases, a doctor may take a pus sample to better evaluate the cause and ensure that the bacteria is not drug-resistant.

Prevention

While abscesses are not entirely avoidable, there are a few simple measures you can take to prevent them:

• Wash your hands often, ideally with an antibacterial cleanser.
• Treat any cuts with care, keeping them clean, covered, and dry until they fully heal.
• Do not share personal items like razors, towels, lipstick, or lip balm.
• Avoid cutting yourself when shaving your underarms or pubic area.

Summary

An abscess looks like a little bump or a pimple that can grow into an inflamed, fluid-filled cyst. Most often, it is caused by a bacteria, called Staphylococcus aureus, which normally exists on the skin and inside the nose. But other culprits, like acne, eczema, or poor hygiene shouldn't be overlooked as possible culprits. Large abscesses must often be drained (by a medical professional only) to ease the pain and discomfort. Depending on the cause, an antibiotic may be justified to finish off the abscess.

A Word From Verywell

If you learn anything about abscesses, remember that you shouldn't underestimate them, particularly the bigger ones. As tempting as it may be to pinch one or try to shrink or drain one, leave the job to your healthcare provider. In expert hands, the procedure won't take long. And you won't run the risk of spreading the bacteria and causing a more serious infection.