Also found in: Dictionary, Thesaurus, Encyclopedia.
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.
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.
circumscribed suppuration characterized by intense surrounding inflammatory reaction that produces induration and thickening of the affected area.
phleg·mon·ous abs·cess(fleg'mŏn-ŭs ab'ses)
Circumscribed suppuration characterized by an intense surrounding inflammatory reaction that produces induration and thickening of the affected area.
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.
a circumscribed abscess in bone, caused by hematogenous infection that becomes a chronic nidus of infection.
see vertebral 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.
a collection of pus not enclosed by a capsule.
facial subcutaneous abscess
a disease of cattle eating hay or pasture containing mature grass awns.
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.
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.
include diaphragmatic, mesenteric, retroperitoneal; many are subclinical; clinical signs include those of chronic peritonitis. Called also omental bursitis.
see malar abscess.
a very large abscess in this site may cause signs of congestive heart failure due to compression of pericardium and venae cavae.
one of a set of small abscesses.
abscess of the mammary gland occurring during lactation.
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.
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.
firm masses above or below the eyes occur in birds as a sequel to chronic respiratory disease and sinusitis.
one associated with acute inflammation of the subcutaneous connective tissue.
acute recurrence of a chronic periapical lesion.
one formed at the seat of the infection.
rete mirabile abscess
see pituitary 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.
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.
one that burrows into tissues and finally points at a distance from the site of origin.