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An abscess is an enclosed collection of liquefied tissue, known as pus, somewhere in the body. It is the result of the body's defensive reaction to foreign material.


There are two types of abscesses, septic and sterile. Most abscesses are septic, which means that they are the result of an infection. Septic abscesses can occur anywhere in the body. Only a germ and the body's immune response are required. In response to the invading germ, white blood cells gather at the infected site and begin producing chemicals called enzymes that attack the germ by digesting it. These enzymes act like acid, killing the germs and breaking them down into small pieces that can be picked up by the circulation and eliminated from the body. Unfortunately, these chemicals also digest body tissues. In most cases, the germ produces similar chemicals. The result is a thick, yellow liquid—pus—containing digested germs, digested tissue, white blood cells, and enzymes.
An abscess is the last stage of a tissue infection that begins with a process called inflammation. Initially, as the invading germ activates the body's immune system, several events occur:
  • Blood flow to the area increases.
  • The temperature of the area increases due to the increased blood supply.
  • The area swells due to the accumulation of water, blood, and other liquids.
  • It turns red.
  • It hurts, because of the irritation from the swelling and the chemical activity.
These four signs—heat, swelling, redness, and pain—characterize inflammation.
As the process progresses, the tissue begins to turn to liquid, and an abscess forms. It is the nature of an abscess to spread as the chemical digestion liquefies more and more tissue. Furthermore, the spreading follows the path of least resistance—the tissues most easily digested. A good example is an abscess just beneath the skin. It most easily continues along beneath the skin rather than working its way through the skin where it could drain its toxic contents. The contents of the abscess also leak into the general circulation and produce symptoms just like any other infection. These include chills, fever, aching, and general discomfort.
Sterile abscesses are sometimes a milder form of the same process caused not by germs but by nonliving irritants such as drugs. If an injected drug like penicillin is not absorbed, it stays where it was injected and may cause enough irritation to generate a sterile abscess—sterile because there is no infection involved. Sterile abscesses are quite likely to turn into hard, solid lumps as they scar, rather than remaining pockets of pus.

Causes and symptoms

Many different agents cause abscesses. The most common are the pus-forming (pyogenic) bacteria like Staphylococcus aureus, which is nearly always the cause of abscesses under the skin. Abscesses near the large bowel, particularly around the anus, may be caused by any of the numerous bacteria found within the large bowel. Brain abscesses and liver abscesses can be caused by any organism that can travel there through the circulation. Bacteria, amoeba, and certain fungi can travel in this fashion. Abscesses in other parts of the body are caused by organisms that normally inhabit nearby structures or that infect them. Some common causes of specific abscesses are:
  • skin abscesses by normal skin flora
  • dental and throat abscesses by mouth flora
  • lung abscesses by normal airway flora, pneumonia germs, or tuberculosis
  • abdominal and anal abscesses by normal bowel flora

Specific types of abscesses

Listed below are some of the more common and important abscesses.
  • Carbuncles and other boils. Skin oil glands (sebaceous glands) on the back or the back of the neck are the ones usually infected. The most common germ involved is Staphylococcus aureus. Acne is a similar condition of sebaceous glands on the face and back.
  • Pilonidal abscess. Many people have as a birth defect a tiny opening in the skin just above the anus. Fecal bacteria can enter this opening, causing an infection and subsequent abscess.
  • Retropharyngeal, parapharyngeal, peritonsillar abscess. As a result of throat infections like strep throat and tonsillitis, bacteria can invade the deeper tissues of the throat and cause an abscess. These abscesses can compromise swallowing and even breathing.
  • Lung abscess. During or after pneumonia, whether it's due to bacteria [common pneumonia], tuberculosis, fungi, parasites, or other germs, abscesses can develop as a complication.
  • Liver abscess. Bacteria or amoeba from the intestines can spread through the blood to the liver and cause abscesses.
  • Psoas abscess. Deep in the back of the abdomen on either side of the lumbar spine lie the psoas muscles. They flex the hips. An abscess can develop in one of these muscles, usually when it spreads from the appendix, the large bowel, or the fallopian tubes.

Key terms

Cellulitis — Inflammation of tissue due to infection.
Enzyme — Any of a number of protein chemicals that can change other chemicals.
Fallopian tubes — Part of the internal female anatomy that carries eggs from the ovaries to the uterus.
Flora — Living inhabitants of a region or area.
Pyogenic — Capable of generating pus. Streptococcus, Staphocococcus, and bowel bacteria are the primary pyogenic organisms.
Sebaceous glands — —Tiny structures in the skin that produce oil (sebum). If they become plugged, sebum collects inside and forms a nurturing place for germs to grow.
Septicemia — The spread of an infectious agent throughout the body by means of the blood stream.
Sinus — A tubular channel connecting one body part with another or with the outside.


The common findings of inflammation—heat, redness, swelling, and pain—easily identify superficial abscesses. Abscesses in other places may produce only generalized symptoms such as fever and discomfort. If the patient's symptoms and physical examination do not help, a physician may have to resort to a battery of tests to locate the site of an abscess, but usually something in the initial evaluation directs the search. Recent or chronic disease in an organ suggests it may be the site of an abscess. Dysfunction of an organ or system—for instance, seizures or altered bowel function—may provide the clue. Pain and tenderness on physical examination are common findings. Sometimes a deep abscess will eat a small channel (sinus) to the surface and begin leaking pus. A sterile abscess may cause only a painful lump deep in the buttock where a shot was given.


Since skin is very resistant to the spread of infection, it acts as a barrier, often keeping the toxic chemicals of an abscess from escaping the body on their own. Thus, the pus must be drained from the abscess by a physician. The surgeon determines when the abscess is ready for drainage and opens a path to the outside, allowing the pus to escape. Ordinarily, the body handles the remaining infection, sometimes with the help of antibiotics or other drugs. The surgeon may leave a drain (a piece of cloth or rubber) in the abscess cavity to prevent it from closing before all the pus has drained out.

Alternative treatment

If an abscess is directly beneath the skin, it will be slowly working its way through the skin as it is more rapidly working its way elsewhere. Since chemicals work faster at higher temperatures, applications of hot compresses to the skin over the abscess will hasten the digestion of the skin and eventually result in its breaking down, releasing the pus spontaneously. This treatment is best reserved for smaller abscesses in relatively less dangerous areas of the body—limbs, trunk, back of the neck. It is also useful for all superficial abscesses in their very early stages. It will "ripen" them.
Contrast hydrotherapy, alternating hot and cold compresses, can also help assist the body in resorption of the abscess. There are two homeopathic remedies that work to rebalance the body in relation to abscess formation, Silica and Hepar sulphuris. In cases of septic abscesses, bentonite clay packs (bentonite clay and a small amount of Hydrastis powder) can be used to draw the infection from the area.


Once the abscess is properly drained, the prognosis is excellent for the condition itself. The reason for the abscess (other diseases the patient has) will determine the overall outcome. If, on the other hand, the abscess ruptures into neighboring areas or permits the infectious agent to spill into the bloodstream, serious or fatal consequences are likely. Abscesses in and around the nasal sinuses, face, ears, and scalp may work their way into the brain. Abscesses within an abdominal organ such as the liver may rupture into the abdominal cavity. In either case, the result is life threatening. Blood poisoning is a term commonly used to describe an infection that has spilled into the blood stream and spread throughout the body from a localized origin. Blood poisoning, known to physicians as septicemia, is also life threatening.
Of special note, abscesses in the hand are more serious than they might appear. Due to the intricate structure and the overriding importance of the hand, any hand infection must be treated promptly and competently.


Infections that are treated early with heat (if superficial) or antibiotics will often resolve without the formation of an abscess. It is even better to avoid infections altogether by taking prompt care of open injuries, particularly puncture wounds. Bites are the most dangerous of all, even more so because they often occur on the hand.



Fauci, Anthony S., et al., editors. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 1997.


a localized collection of pus in a cavity formed by the disintegration of tissue. Abscesses are usually caused by specific microorganisms that invade the tissues, often by way of small wounds or breaks in the skin. An abscess is a natural defense mechanism in which the body attempts to localize an infection and wall off the microorganisms so that they cannot spread throughout the body. As the microorganisms destroy the tissue, an increased supply of blood is rushed to the area. The cells, bacteria, and dead tissue accumulate to form a clump of cream-colored liquid, which is the pus. The accumulating pus and the adjacent swollen, inflamed tissues press against the nerves, causing pain. The concentration of blood in the area causes redness. The abscess sometimes “comes to a head” by itself and breaks through the skin or other tissues, allowing the pus to drain. Local applications of heat may be used to facilitate localization and drainage.
Abscess, cross section.
alveolar abscess a localized suppurative inflammation of tissues about the apex of the root of a tooth.
amebic abscess an abscess cavity of the liver resulting from liquefaction necrosis due to entrance of Entamoeba histolytica into the portal circulation in amebiasis; amebic abscesses may also affect the lungs, brain, and spleen.
Bartholin abscess acute infection of a Bartholin gland with symptoms including pain, swelling, cellulitis of the vulva, and dyspareunia. Treatment is incision and drainage of the abscess. Cultures should be obtained to rule out infections by Neisseria gonorrhoeae or Chlamydia.
Bezold's abscess one deep in the neck resulting from a complication of acute mastoiditis.
brain abscess see brain abscess.
Brodie's abscess a circumscribed abscess in bone, caused by hematogenous infection, that becomes a chronic nidus of infection.
cold abscess one of slow development and with little inflammation, usually tuberculous.
diffuse abscess an uncircumscribed abscess whose pus is diffused in the surrounding tissues.
gas abscess one containing gas, caused by gas-forming bacteria such as Clostridium perfringens. Called also Welch's abscess.
miliary abscess one composed of numerous small collections of pus.
pancreatic abscess one that occurs as a complication of acute pancreatitis or postoperative pancreatitis caused by secondary bacterial contamination.
perianal abscess one beneath the skin of the anus and the anal canal.
periapical abscess inflammation with pus in the tissues surrounding the apex of a tooth.
periodontal abscess a localized collection of pus in the periodontal tissue.
peritonsillar abscess a localized accumulation of pus in the peritonsillar tissue subsequent to suppurative inflammation of the tonsil; called also quinsy.
phlegmonous abscess one associated with acute inflammation of the subcutaneous connective tissue.
stitch abscess one developed about a stitch or suture.
thecal abscess one in the sheath of a tendon.
wandering abscess one that burrows into tissues and finally points at a distance from the site of origin.
Welch's abscess gas abscess.


(ab'ses), Avoid the misspellings abcess and absess. Avoid the mispronunciation ab'sĕ-sēz of the plural of this word.
1. A circumscribed collection of purulent exudate frequently associated with swelling and other signs of inflammation.
2. A cavity formed by liquefactive necrosis within solid tissue.
[L. abscessus, a going away]


/ab·scess/ (ab´ses) a localized collection of pus in a cavity formed by disintegration of tissues.
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Cross section of abscess.
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Abscesses of breast.

amebic abscess  one caused by Entamoeba histolytica, usually occurring in the liver but also in the lungs, brain, and spleen.
apical abscess  a suppurative inflammatory reaction involving the tissues surrounding the apical portion of a tooth, occurring in acute and chronic forms.
appendiceal abscess , appendicular abscess one resulting from perforation of an acutely inflamed appendix.
Bezold's abscess  one deep in the neck as a complication of acute mastoiditis.
brain abscess  one affecting the brain as a result of extension of an infection (e.g., otitis media) from an adjacent area, or through bloodborne infection.
Brodie's abscess  a roughly spherical region of bone destruction, filled with pus or connective tissue, usually in the metaphyseal region of long bones and caused by Staphylococcus aureus or S. albus.
cold abscess 
1. one of slow development and with little inflammation.
diffuse abscess  a collection of pus not enclosed by a capsule.
gas abscess  one containing gas, caused by gas-forming bacteria such as Clostridium perfringens.
miliary abscess  one of a set of small multiple abscesses.
Pautrier's abscess  see under microabscess.
peritonsillar abscess  one in the connective tissue of the tonsil capsule, from suppuration of the tonsil.
phlegmonous abscess  one associated with acute inflammation of the subcutaneous connective tissue.
ring abscess  a ring-shaped purulent infiltration at the periphery of the cornea.
shirt-stud abscess  one separated into two cavities connected by a narrow channel.
stitch abscess  one developed about a stitch or suture.
thecal abscess  one arising in a sheath, as in a tendon sheath.
tuberculous abscess  one due to infection with tubercle bacilli.
vitreous abscess  an abscess of the vitreous humor of the eye due to infection, trauma, or foreign body.
wandering abscess  one that burrows into tissues and finally points at a distance from the site of origin.
Welch's abscess  gas a.


A localized collection of pus in part of the body, formed by tissue disintegration and surrounded by an inflamed area.
intr.v. ab·scessed, ab·scessing, ab·scesses
To form an abscess.


Etymology: L, abscedere, to go away
1 a cavity containing pus and surrounded by inflamed tissue, formed as a result of suppuration in a localized infection, characteristically caused by staphylococci but also caused by parasites and foreign substances. Healing usually occurs when an abscess drains, is incised, or is permanently removed from the body. If an abscess is deep in tissue, drainage is done by means of a sinus tract that connects it to the surface. In a sterile abscess, the contents are not the result of pyogenic bacteria. Abscesses are able to form in almost any location on or within the body.
2 an abscess that develops anywhere along the root length of a tooth. It is usually characterized by pain caused by the pressure of pus against the nerve tissue within the tooth or within the periodontal tissues, redness caused by blood accumulation, and swelling caused by the suppuration. The source of the bacteria that causes the infection is the normal oral flora. See also periapical abscess, periodontal abscess, and tooth abscess.
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A local accumulation of pus in tissues, organs or spaces, usually due to a bacterial infection. The bacteria cultured often reflect the native flora of the region affected.


Infectious disease A local accumulation of pus in tissues, organs or confined spaces, almost invariably due to an infection Microbiology The bacteria cultured from an abscess are largely a function of the region affected. See Abdominal abscess, Alveolar abscess, Amebic abscess, Apical abscess, Areolar gland abscess, Brain abscess, Brodie's abscess, Cold abscess, Collar button abscess, Collar-stud abscess, Crypt abscess, Intracranial abscess, Kogoj's abscess, Microabscess, Munro's microabscess, Perforating abscess, Peritonsillar abscess, Ring abscess, Satellite abscess, Stellate abscess, Walled abscess.


1. A circumscribed collection of purulent exudate appearing in an acute or chronic localized infection, caused by tissue destruction and frequently associated with swelling, pain, and other signs of inflammation.
2. A cavity formed by liquefactive necrosis within solid tissue; healing may be promoted by excision and drainage.
[L. abscessus, a going away]


(ab'ses) [L. abscessus, a going away]
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ANTECUBITAL ABSCESS: Antecubital abscess opened to allow drainage of infection
A localized collection of pus in any body part, resulting from invasion of a pyogenic bacterium or other pathogen. Staphylococcus aureus, e.g., methicillin-resistant S. aureus (MRSA), is a common cause. The abscess is surrounded by a membrane of variable strength created by macrophages, fibrin, and granulation tissue. Abscesses can disrupt function in adjacent tissues and can be life threatening in some circumstances, e.g., in the lung or within the peritoneal cavity. illustration; inflammation; pus; suppuration;
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acute abscess

An abscess associated with significant inflammation, producing intense heat, redness, swelling, and throbbing pain. The tissue over the abscess becomes elevated, soft, and eventually unstable (fluctuant) and discolored as the abscess comes to a head (points). An abscess can rupture spontaneously or be drained via an incision. If it is left untreated, the pathogens may spread to adjacent tissues or to other parts of the body via the bloodstream. Appearance of or increase in fever may indicate sepsis.

alveolar abscess

An abscess around the root of a tooth in the alveolar cavity. It is usually the result of necrosis and infection of dental pulp following dental caries.
See: periapical abscess

amebic abscess

An abscess caused by Entamoeba histolytica. Synonym: endamebic abscess

anorectal abscess

An abscess in the ischiorectal fossa. It may occur in patients with Crohn disease, diabetes mellitus, or anal fissures more often than in other patients. Incision, drainage, and antibiotics usually provide effective treatment. Synonym: rectal abscess; Synonym: ischiorectal abscess

apical abscess

1. An abscess at the apex of a lung.
2. Periapical abscess.

appendicular abscess

An abscess around an inflamed or ruptured vermiform appendix.

axillary abscess

An abscess or multiple abscesses in the axilla, e.g., in patients with hidradenitis suppurativa.

Bartholin abscess

See: Bartholin, Caspar (the younger)

bicameral abscess

An abscess with two pockets.

bile duct abscess

An abscess of the bile duct. Synonym: cholangitic abscess

biliary abscess

An abscess of the gallbladder. It is an infrequent complication of cholangitis or obstruction of the bile duct.

bone abscess

Brodie abscess.

brain abscess

An intracranial abscess involving the brain or its membranes. It is seldom primary but usually occurs secondary to infections of the middle ear, nasal sinuses, face, or skull or from contamination from penetrating wounds or skull fractures. It may also have a metastatic origin arising from septic foci in the lungs (bronchiectasis, empyema, lung abscess), in bone (osteomyelitis), or in the heart (endocarditis). Infection of nerve tissue by the invading organism results in necrosis and liquefaction of the tissue, with edema of surrounding tissues. Brain abscesses may be acute, subacute, or chronic. Their clinical manifestations depend on the part of the brain involved, the size of the abscess, the virulence of the infecting organism, and other factors. Synonym: cerebral abscess; intracranial abscess


Symptoms may include headache, fever, vomiting, malaise, irritability, seizures, or paralysis.


The usual treatment is chemotherapy. Surgical drainage may be required.

breast abscess

Mammary abscess.

Brodie abscess

See: Brodie, Sir Benjamin Collins

bursal abscess

An abscess in a bursa.

canalicular abscess

A breast abscess that discharges into the milk ducts.

caseous abscess

An abscess in which the pus has a cheesy appearance.

cerebral abscess

Brain abscess.

cholangitic abscess

Biliary abscess.

chronic abscess

An abscess with pus but without signs of inflammation. It usually develops slowly as a result of liquefaction of tuberculous tissue. It may occur anywhere in or on the body but more frequently in the spine, hips, genitourinary tract, and lymph glands. Symptoms may be very mild. Pain, when present, is caused by pressure on surrounding parts; tenderness is often absent. Chronic septic changes accompanied by afternoon fever may occur. Amyloid disease may develop if the abscess persists for a prolonged period.
Synonym: cold abscess

circumtonsillar abscess

Peritonsillar abscess.

cold abscess

Chronic abscess.

collar-button abscesses

Two pus-containing cavities, one larger than the other, connected by a narrow channel.

dental abscess

An acute inflammatory infection within the maxilla or mandible. See: periapical abscess; periodontal abscess

dentoalveolar abscess

Periapical abscess.

diffuse abscess

An abscess not circumscribed by a well-defined capsule.

dry abscess

An abscess that disappears without pointing or breaking.

embolic abscess

Metastatic abscess.

emphysematous abscess

An abscess containing air or gas, produced by organisms such as Clostridium perfringens. Synonym: gas abscess; tympanitic abscess

endamebic abscess

Amebic abscess.

epidural abscess

Extradural abscess.

extradural abscess

An abscess on the dura mater, an occasional cause of back pain in febrile patients, usually in those who inject drugs. Synonym: epidural abscess

fecal abscess

An abscess containing both pus and stool. Synonym: stercoraceous abscess; stercoral abscess

filarial abscess

An abscess caused by parasitic infection with microfilariae.

follicular abscess

An abscess in a follicle.

fungal abscess

An abscess caused by a fungus, e.g., mycetoma.
Synonym: mycotic abscess

gas abscess

Emphysematous abscess.

gingival abscess

An abscess of the gum.

helminthic abscess

Worm abscess.

hemorrhagic abscess

An abscess containing blood.

hepatic abscess

Liver abscess.

hot abscess

Acute abscess.

hypostatic abscess

Metastatic abscess.

idiopathic abscess

An abscess of unknown cause.

iliac abscess

An abscess in the iliac region.

iliopsoas abscess

An abscess in the psoas and iliacus muscles. It typically results from a local or regional spread of an intestinal or renal abscess or from a blood-borne infection, e.g., after a drug injection.
Synonym: psoas abscess

intracranial abscess

Brain abscess.

intradural abscess

An abscess within the layers of the dura mater.

intraperitoneal abscess

Peritoneal abscess.

ischiorectal abscess

Anorectal abscess.

kidney abscess

An abscess in the kidney, typically following pyelonephritis or a blood-borne infection. The most common causative organisms are gram-negative bacteria from the lower urinary tract that spread to the kidneys and Staphylococcus aureus from a blood-borne infection. Immunocompromised patients may develop abscesses caused by Nocardia, Candida, or Aspergillus. Occasionally, Mycobacterium tuberculosis and Echinococcus are responsible agents. Synonym: renal abscess


Antimicrobial agents are used in combination with surgical drainage. Occasionally, nephrectomy or retroperitoneal exploration is required.

lacrimal abscess

An abscess in a lacrimal gland or in a lacrimal duct.

lateral alveolar abscess

An abscess in periodontal tissue.

liver abscess

, abscess of the liver
An abscess in the liver caused by pathogenic organisms such as those of species of Bacteroides, Streptococcus, Staphylococcus, or Entamoeba histolytica.


The patient will have high fevers; sweats and chills; and an enlarged, painful, tender liver. Pus may be obtained by aspiration.


Embolic (multiple) abscesses are generally fatal. Liver abscesses may heal after they have been evacuated and treated with antibiotics.

See: hepatic abscess

lumbar abscess

An abscess in the lumbar region.

lung abscess

An abscess in lung tissue, caused by anaerobic bacteria such as Staphylococcus aureus or Nocardia species.

lymphatic abscess

An abscess of a lymph node.

mammary abscess

An abscess in the female breast, esp. one involving the glandular tissue. It usually occurs during lactation or weaning.
Synonym: breast abscess

mastoid abscess

An abscess of the mastoid portion of the temporal bone.

metastatic abscess

A secondary abscess at a distance from the focus of infection.
Synonym: embolic abscess; hypostatic abscess; wandering abscess

miliary abscesses

Multiple small embolic abscesses.

milk abscess

A mammary abscess during lactation.

mycotic abscess

Fungal abscess.

nocardial abscess

An abscess caused by Nocardia, e.g., in the lung).

orbital abscess

An abscess in the orbit of the eye.

palatal abscess

An abscess in a maxillary tooth, erupting toward the palate.

palmar abscess

An abscess in the tissues of the palm of the hand.

pancreatic abscess

An abscess of pancreatic tissue, usually as a complication of acute pancreatitis or abdominal surgery.

parafrenal abscess

An abscess on the side of the frenulum of the penis.

parametric abscess

An abscess between the folds of the broad ligaments of the uterus.

paranephric abscess

An abscess in the tissues around the kidney.
Synonym: perinephric abscess

parapancreatic abscess

An abscess in the tissues adjacent to the pancreas.
Synonym: peripancreatic abscess

parietal abscess

A periodontal abscess arising in the periodontal tissue other than the orifice through which the vascular supply enters the dental pulp.

parotid abscess

An abscess of the parotid gland.

pelvic abscess

An abscess of the pelvic peritoneum, esp. in the pouch of Douglas. It may arise as a complication of a sexually transmitted disease or diverticulitis.

perianal abscess

An abscess of the skin around the anus. It usually results from obstruction of intestinal crypts and subsequent fistula formation in the skin.
Synonym: periproctic abscess

periapical abscess

An abscess at the apex of a tooth, usually resulting from dental caries or tooth trauma. It may be classified further as an acute periapical abscess, a chronic periapical abscess, a periapical granuloma, or a radicular cyst. Synonym: apical abscess (2); dentoalveolar abscess

pericemental abscess

An alveolar abscess not involving the apex of a tooth.

pericoronal abscess


peridental abscess

An abscess of periodontal tissue.

perinephric abscess

Paranephric abscess.

periodontal abscess

An acute or chronic abscess found in the gingiva, periodontal pockets, or periodontal ligament.

peripancreatic abscess

Parapancreatic abscess.

peripleuritic abscess

An abscess in the tissue surrounding the parietal pleura.

periproctic abscess

Perianal abscess.

peritoneal abscess

An abscess within the peritoneal cavity usually following peritonitis. It is usually caused by enteric bacteria, e.g., Escherichia coli, enterococci, or Klebsiella.
Synonym: intraperitoneal abscess

peritonsillar abscess

An abscess of the tissue around the tonsillar capsule. Needle aspiration of the abscess, with subsequent antibiotic therapy, is an effective treatment in 90% of cases. Synonym: circumtonsillar abscess

periureteral abscess

An abscess in the tissue around a ureter.

periurethral abscess

An abscess in tissue surrounding the urethra.

perivesical abscess

An abscess in tissue around the urinary bladder.

pneumococcic abscess

An abscess due to infection with pneumococci.

prelacrimal abscess

An abscess of the lacrimal sac, producing an inflamed, tender swelling at the inner canthus of the eye.

premammary abscess

A subcutaneous or subareolar abscess of the mammary gland.

prostatic abscess

An abscess within the prostate gland.

protozoal abscess

An abscess caused by a protozoon.

psoas abscess

Iliopsoas abscess.

pulp abscess

1. An abscess in the pulp chamber of a tooth.
2. An abscess of the tissues of the pulp of a finger.

pyemic abscess

A metastatic abscess, usually multiple, due to pyogenic organisms.

rectal abscess

Anorectal abscess.

renal abscess

Kidney abscess.

retrocecal abscess

An abscess located behind the cecum. It is an occasional, severe complication of a ruptured appendix or Crohn disease.

retromammary abscess

An abscess between the mammary gland and the chest wall.

retroperitoneal abscess

An abscess located between the peritoneum and the posterior abdominal wall. It may arise from an abscess in the kidney or from the spread of an intraperitoneal infection posteriorly.

retropharyngeal abscess

An abscess of the lymph nodes in the walls of the pharynx. It sometimes simulates diphtheritic pharyngitis.


Staphylococcus aureus and group A hemolytic streptococcus are the most common pathogens.


Typically, a history of pharyngitis is elicited. This is followed by high fever, dysphagia, and refusal to eat. The condition progresses to respiratory distress with hyperextension of the head (“sniffing position”), tachypnea, labored breathing, and drooling. An exquisitely tender bulge in the pharyngeal wall is usually evident.


A retropharyngeal abscess, if fluctuant, should be treated with incision and drainage. If recognized before becoming fluctuant, the abscess should be treated with antibiotics, intravenously administered if the patient is unable to swallow.

retrovesical abscess

An abscess behind the bladder.

root abscess

A colloquial and veterinary term for periapical abscess.

runaround abscess

A colloquial term for a bacterial infection that surrounds a fingernail; a paronychia.

sacrococcygeal abscess

An abscess over the sacrum and coccyx.

septicemic abscess

An abscess resulting from septicemia.

spermatic abscess

An abscess of the seminiferous tubules.

spinal abscess

An abscess due to necrosis of a vertebra.

splenic abscess

An abscess of the spleen. It may arise either from the spread of infection from a neighboring organ (that is, a diverticular abscess or a ruptured gastric ulcer) or from hematogenous spread in patients with infective endocarditis.

stercoraceous abscess

Fecal abscess

stercoral abscess

Fecal abscess.

sterile abscess

An abscess from which microorganisms cannot be cultivated, an occasional complication of intramuscular injection.

stitch abscess

An abscess formed about a stitch or suture.

streptococcal abscess

An abscess caused by streptococci.

subaponeurotic abscess

An abscess beneath an aponeurosis or fascia.

subarachnoid abscess

An abscess of the midlayer of the covering of the brain and spinal cord.

subareolar abscess

An abscess underneath the areola of the mammary gland, sometimes draining through the nipple.

subdiaphragmatic abscess

An abscess beneath the diaphragm, e.g., an hepatic, splenic, or interperitoneal abscess. Synonym: subphrenic abscess

subdural abscess

An abscess beneath the dura of the brain or spinal cord.

subfascial abscess

An abscess beneath the fascia.

subgaleal abscess

An abscess beneath the galea aponeuroticai (the epicranial aponeurosis).

subpectoral abscess

An abscess beneath the pectoral muscles.

subperiosteal abscess

A bone abscess below the periosteum.

subperitoneal abscess

An abscess between the parietal peritoneum and the abdominal wall.

subphrenic abscess

Subdiaphragmatic abscess.

subscapular abscess

An abscess between the serratus anterior and the posterior thoracic wall.

subungual abscess

An abscess beneath the fingernail. It may follow injury from a pin, needle, or splinter.

sudoriparous abscess

An abscess of a sweat gland.

suprahepatic abscess

An abscess in the suspensory ligament between the liver and the diaphragm.

syphilitic abscess

An abscess occurring in the tertiary stage of syphilis, esp. in bone.

thecal abscess

A spinal epidural abscess.

thymus abscess

An abscess of the thymus.

tonsillar abscess

Acute suppurative tonsillitis.

tooth abscess

Alveolar abscess.

tropical abscess

An amebic abscess of the liver.

tuberculous abscess

Chronic abscess.

tubo-ovarian abscess

An abscess involving both the fallopian tube and the ovary. It is typically transmitted sexually.

tympanitic abscess

Emphysematous abscess.

tympanocervical abscess

An abscess arising in the tympanum and extending to the neck.

tympanomastoid abscess

An abscess of both the tympanum and the mastoid.

urethral abscess

An abscess in the urethra.

urinary abscess

An abscess caused by escape of urine into the tissues.

urinous abscess

An abscess that contains pus and urine.

verminous abscess

Worm abscess.

wandering abscess

Metastatic abscess.

warm abscess

Acute abscess.

worm abscess

An abscess caused by or containing insect larvae, worms, or other animal parasites. Synonym: helminthic abscess; verminous abscess


A cavity full of PUS surrounded by inflamed or dying tissue, or by dense fibrous tissue which cuts off the blood supply to the centre. Abscesses are nearly always caused by INFECTION and the organisms concerned often persist within them. Some, however, become sterile. They can seldom be effectively treated with antibiotics and must be opened and the contents drained surgically for proper resolution. See also ANTIBIOMA.


a collection of PUS surrounded by an inflamed area in any tissue or organ of an animal.


pus formation due to a local acute or chronic bacterial infection, with severe acute inflammation, cellulitis, tissue liquefaction, cavity formation and necrosis, and general malaise, pyrexia and lymphadenitis
  • Brodie's abscess pus from osteomyelitis or osseous tuberculosis tracking along a tissue plane and emerging at a distant skin site

  • cold abscess chronic tuberculous abscess with characteristic lack of signs of inflammation or infection

  • perforating abscess an abscess with breakdown of adjacent tissues and contiguous spread of infection


An accumulation of pus located in infected tissue.


1. Circumscribed collection of purulent exudate.
2. Cavity formed by liquefactive necrosis within solid tissue.
[L. abscessus, a going away]

abscess (ab´ses),

n a localized accumulation of suppuration in a confined space formed by tissue disintegration.
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abscess, alveolar,
abscess, apical,
abscess, dentoalveolar,
abscess, gingival,
n a superficial periodontal abscess occurring within the free gingival sulcus surrounding the tooth, frequently caused by the impaction of food.
abscess, lateral,
abscess, periapical
n an abscess involving the apical region of the root, alveolus, and surrounding bone as a result of pulpal disease.
abscess, pericoronal,
abscess, periodontal,
n an abscess involving the attachment tissues and alveolar bone as a result of periodontal disease.
abscess, periradicular
n an abscess involving the periradicular region of the root, alveolus, and surrounding bone as a result of pulpal disease.
abscess, pulpal,
n an abscess occurring within pulpal tissue.
abscess, staphylococcal
n an abscess caused by the bacteria
S. aureus, an infectious agent that can be transmitted via saliva and other discharges of the body. The incubation period is 4 to 10 days; the duration of the abscess varies and is indefinite. The bacteria are communicable throughout the drainage period of the lesions and while the carrier state continues.


a localized collection of pus in a cavity formed by the disintegration of tissue. Most abscesses are formed by invasion of tissues by bacteria, but some are caused by fungi or protozoa or even helminths, and some are sterile. Their effects are determined by their location and the pressure that they exert on nearby organs, and the degree of toxemia that they create from their bacterial content and the amount of tissue destroyed. So that for a reasonably active abscess the syndrome presented will be one of local pain, anorexia and fever, and a leukocytosis. For specific abscesses see under anatomical sites, e.g. brain abscess.

Brodie's abscess
a circumscribed abscess in bone, caused by hematogenous infection that becomes a chronic nidus of infection.
cervical abscess
see vertebral abscess.
cold abscess
one of slow development and with little inflammation, e.g. caseous lymphadenitis of sheep and goat.
cornea stromal abscess
small ulcers or puncture wounds of the corneal epithelium may permit entry of bacteria then heal, creating an abscess. Particularly important in horses.
diffuse abscess
a collection of pus not enclosed by a capsule.
facial subcutaneous abscess
a disease of cattle eating hay or pasture containing mature grass awns.
gas abscess
one containing gas, caused by gas-forming bacteria such as Clostridium perfringens.
grass seed abscess
in cattle occurs as a cold, subcutaneous abscess at the throat or on the mandible and is often diagnosed but rarely confirmed. In dogs it occurs in many sites, but most commonly between the toes. The causative grass awn(s) may be recovered by forceps or, in more extensive lesions, surgical exploration.
infraorbital abscess
occurs in birds as a sequel to chronic upper respiratory infection with sinusitis.
injection site abscess
an iatrogenic lesion resulting from incomplete skin disinfection before injection; usually contains Arcanobacterium pyogenes.
intra-abdominal abscess
include diaphragmatic, mesenteric, retroperitoneal; many are subclinical; clinical signs include those of chronic peritonitis. Called also omental bursitis.
maxillary abscess
see malar abscess.
mediastinal abscess
a very large abscess in this site may cause signs of congestive heart failure due to compression of pericardium and venae cavae.
miliary abscess
one of a set of small abscesses.
milk abscess
abscess of the mammary gland occurring during lactation.
pectoral abscess
a disease of horses in which abscesses occur in the pectoral muscles and ventral midline, and in some cases in internal organs, causing local pain and swelling and eventually rupturing and draining to the exterior. Endemic to areas of California, Texas and Colorado in the USA where it is also known as pigeon fever and has epidemic occurrence in the autumn of some years with a possible insect vector transmission. Caused by Corynebacterium pseudotuberculosis.
periapical abscess
inflammation and destruction of dental pulp and surrounding tissues, including the periodontal membrane and alveolar bone. The radiographic appearance is a translucency of the tooth apex and adjacent alveolar bone. Most common in dogs.
periorbital abscess
firm masses above or below the eyes occur in birds as a sequel to chronic respiratory disease and sinusitis.
phlegmonous abscess
one associated with acute inflammation of the subcutaneous connective tissue.
phoenix abscess
acute recurrence of a chronic periapical lesion.
primary abscess
one formed at the seat of the infection.
rete mirabile abscess
see pituitary abscess.
retroarticular abscess
one located between the intermediate phalanx and the deep flexor tendon in the hooves of cattle. It may be caused by extension of infection from the navicular bursa or from suppurative arthritis of the distal interphalangeal joint.
retrobulbar abscess
behind the orbit of the eye; cause pain on opening of the mouth, chemosis and exophthalmos, protrusion of the nictitating membrane, and systemic signs of infection. Most common in dogs and cats.
stitch abscess, suture abscess
one developed about a stitch or suture.
vertebral body/epidural abscess
usually of cervical or lumbar vertebrae; causes compression of cord manifested by incoordination, paresis, paralysis.
wandering abscess
one that burrows into tissues and finally points at a distance from the site of origin.
References in periodicals archive ?
Order a copy of Abdominal Abscess Global Clinical Trials Review, H2, 2015 market research report at http://www.
Brucella testicular abscess case presenting as a testicular mass: Can color Doppler sonography be useful in differentiation?
Patients with a Listeria brain abscess should receive treatment for at least 6 weeks and be followed by serial neurological imaging, with MRI as the preferred modality (4).
Spinal epidural abscess (SEA) is diagnosed in approximately 1 in 20,000 hospital admissions.
Primary Klebsiella pneumoniae liver abscess with metastatic spread to lung and eye, a North-European case report of an emerging syndrome.
Dr Essam Elgamal, a paediatric neurosurgeon who led the child's operation, said they removed the abscess via a craniotomy.
Despite the extremely low incidence, brain abscess caused by bacterial infection has a high mortality rate of 30% and is therefore a disease with poor prognosis for both mother and fetus, regardless of the state of pregnancy.
Treatment of an early abscess or Quinsy is by antibiotics while a fully developed abscess requires hospital admission where antibiotics are given through a drip (intravenously).
The CT scans failed to show gallstones in the two abscesses even though gallstones eventually were found on excision of the abdominal wall abscess.
The condition of a cerebral abscess arising from sinusitis is extremely rare and difficult to diagnose.
Compared with patients who did not receive anti-TNF therapy after drainage, those who did were much less likely to develop a recurrence of abscess.
There have been a few subsequent pediatric case reports in the literature, but overall the incidence of this complication remains rare in comparison to adults, in whom up to 30% to 40% of patients with native valve IE have evidence of a myocardial abscess.