Abscess
A pus-filled pocket caused by infection, often requiring drainage.
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An abscess is a pocket of pus that forms inside body tissue, most often due to a bacterial infection. Common signs include redness, pain, warmth, and swelling, and the swollen area may feel fluid-filled when pressed. The redness typically spreads beyond the swelling itself.
Boils and carbuncles are types of abscesses linked to hair follicles, with carbuncles being larger. A cyst is similar but contains material other than pus and has a clearly defined wall. Abscesses can develop on the skin, inside internal organs, or after surgery.
Causes
Bacterial infection is the usual cause, and often multiple types of bacteria are involved in a single abscess. Worldwide, methicillin-resistant Staphylococcus aureus is a common culprit, and skin abscesses are overwhelmingly caused by S. aureus.
Parasites rarely cause abscesses, mostly in the developing world. A skin abscess is typically diagnosed by its appearance and confirmed by cutting it open; ultrasound can help if the diagnosis is unclear. For abscesses near the anus, a CT scan may be needed to check for deeper infection.
Primary closure
The standard treatment for most skin or soft tissue abscesses is cutting it open and draining the pus. Antibiotics may also help. There is limited evidence that packing the empty cavity with gauze is unnecessary, and closing the cavity right after draining—rather than leaving it open—might speed healing without raising the risk of recurrence. Simply sucking out the pus with a needle is often not enough.
Epidemiology
Skin abscesses are common, and some studies suggest they have become more frequent over the last two decades. Intravenous drug use is a major risk factor, with rates as high as 65% among users. In 2005, about 3.2 million people visited U.S. emergency departments for abscesses, and in Australia, roughly 13,000 people were hospitalized for the condition in 2008.
Signs and symptoms
Abscesses can occur in any tissue but are most common on the skin, where they may be superficial pustules (boils) or deep abscesses. They can also form in the lungs, brain, teeth, kidneys, and tonsils.
Major complications include the spread of pus to nearby or distant tissues and extensive tissue death (gangrene). Symptoms of a skin abscess include redness, heat, swelling, pain, and loss of function, sometimes with fever and chills. Superficial abscesses may feel wavy when pressed due to pus movement.
Lore & Background
Abscesses are localized collections of pus resulting from bacterial infection, though parasites can rarely cause them, especially in the developing world. The most common bacteria involved is Staphylococcus aureus, with methicillin-resistant Staphylococcus aureus (MRSA) being prevalent in many areas. Skin abscesses overwhelmingly involve S. aureus, while internal abscesses can occur in organs such as the lungs, brain, and kidneys.
Diagnosis of a skin abscess is typically based on appearance and confirmed by cutting it open; ultrasound or CT may be used for unclear cases or deeper infections. Standard treatment is incision and drainage, with antibiotics sometimes added for severe cases, rapid progression, or immunosuppression. Packing the cavity with gauze after drainage may not be beneficial, and closing the cavity immediately might speed healing without increasing recurrence risk.
Risk factors include intravenous drug use, with rates as high as 65% among users. Skin abscesses are common and have become more frequent in recent decades. In 2005, 3.2 million people visited American emergency departments for abscesses, and in Australia, about 13,000 people were hospitalized in 2008 with the condition.
Reader's Guide
Abscesses are a significant medical condition due to their frequency and potential severity. They represent the body's attempt to wall off infection, but can lead to complications such as spreading infection or gangrene if untreated. The rise of methicillin-resistant Staphylococcus aureus has complicated treatment, as traditional antibiotics may be ineffective. Incision and drainage remains the cornerstone of treatment, though antibiotics are reserved for specific cases.
The condition's association with intravenous drug use highlights public health challenges. Internal abscesses are particularly dangerous and often require prompt medical attention. Understanding abscesses is crucial for both clinical management and prevention, especially in at-risk populations.
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Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Abscess (CC BY-SA 4.0).
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