abcess

An abscess is a localized collection of pus that forms within tissue, organ, or confined spaces as a result of infection and inflammation. The term abcess is a common misspelling of abscess and is not standard in medical usage.

Causes and risk factors: Most abscesses are caused by bacterial infection, notably Staphylococcus aureus and Streptococcus species; anaerobes may be involved in skin and dental origin; fungi or parasites in certain contexts. They can arise after minor trauma or from infection spreading from an adjacent site. Risk factors include diabetes, immune suppression, poor wound care, and chronic dermatitis.

Pathophysiology and sites: Bacteria trigger an inflammatory response with neutrophils and tissue destruction, leading to pus accumulation and a fibrous capsule around the cavity—an abscess wall. Abscesses are common on the skin (pocketed boils or carbuncles), in the teeth (periapical abscess), and in organs such as the liver, lungs, brain, or sinuses.

Clinical features: Local signs include swelling, redness, warmth, and severe throbbing pain; fever, malaise, and fatigue may occur. If the abscess drains spontaneously, relief often follows.

Diagnosis and management: Diagnosis is based on history and examination; imaging such as ultrasound or CT may define extent; sample of purulent material for culture can guide therapy. Primary treatment usually involves incision and drainage for a localized skin abscess. Antibiotics are typically added when there is surrounding cellulitis, systemic illness, immune compromise, deep-seated infection, or failure to drain. Antibiotic choices depend on site and organisms and may target skin flora or specific pathogens.

Prognosis and complications: Most uncomplicated abscesses heal after adequate drainage, but complications include spread of infection to adjacent structures, sepsis, fistula formation, or chronic abscess formation.