Abscess
From Wikipedia, the free encyclopedia
- For the death metal band, see Abscess (band).
An abscess is a collection of pus that has accumulated in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e.g. splinters or bullet wounds). It is a defensive reaction of the tissue to prevent the spread of infectious materials to other parts of the body.
The organisms or foreign materials that have gained access to a part of tissue kill the local cells, resulting in the release of toxins. The toxins trigger an inflammatory response, which 1) draws huge amounts of white blood cells to the area and 2) increases the regional blood flow.
The final structure of the abscess is an abscess wall that is formed by the adjacent healthy cells in an attempt to build a barrier around the pus that limits the infected material from neighboring structures and also limits immune cells from attacking the bacteria.
Abscesses must be differentiated from empyemas, which are accumulations of pus in a pre-existing rather than a newly formed anatomical cavity.
Contents |
[edit] Manifestations
The cardinal symptoms and signs of any kind of inflammatory process are redness, heat, swelling, pain and loss of function. Abscesses may occur in any kind of solid tissue but most frequently on skin surface (where they may be superficial pustules (boils) or deep skin abscesses), in the lungs, brain, kidneys and tonsils. Major complications are spreading of the abscess material to adjacent or remote tissues and extensive regional tissue death (gangrene). Abscesses in most parts of the body rarely heal themselves, so prompt medical attention is indicated at the first suspicion of an abscess.
[edit] Treatment
The abscess should be inspected to identify if foreign objects are a cause, requiring surgical removal. Surgical drainage of the abscess (e.g. lancing) is usually indicated once the abscess has developed from a harder serous inflammation to a softer pus stage. This is expressed in the Latin medical aphorism Ubi pus, ibi evacua.
As Staphylococcus aureus bacteria is a common cause, an anti-Staphylococcus antibiotic such as Flucloxacillin or dicloxacillin is used. It is important to note that antibiotic therapy alone without surgical drainage of the abscess is seldom effective. If foreign objects are not the cause, surgical removal is not needed, but for a normal infection a doctor will prescribe antibiotics and painkillers to treat the abscess.
In critical areas where surgery presents a high risk, surgery may be delayed or used as a last resort. The drainage of a lung abscess may be performed by positioning the patient in a way that enables the contents to be discharged via the respiratory tract. Warm compresses and elevation of the limb may be beneficial for skin abscess.
[edit] Recurrent infections
For recurrent infections due to [Staphylococcus], consider the following measures:
- Topical mupirocin applied to the nares [1]. In this randomized controlled trial, patients used nasal mupirocin twice daily 5 days a month for 1 year.
- Chlorhexidine baths [2], In a randomized controlled trial, nasal recolonization with S. aureus occurred at 12 weeks in 24% of nursing home residents receiving mupirocin ointment alone (6/25) and in 15% of residents receiving mupirocin ointment plus chlorhexidine baths daily for the first three days of mupirocin treatment (4/27). Although these results did not reach statistical significance, the baths are an easy treatment.
[edit] Perianal abscess
Perianal abscesses can be seen in patients with for example inflammatory bowel disease (such as Crohn's disease) or diabetes. Often the abscess will start as an internal wound caused by ulceration or hard stool. This wound typically becomes infected as a result of the normal presence of feces in the rectal area, and then develops into an abscess. This often presents itself as a lump of tissue near the anus which grows larger and more painful with the passage of time.
Like other abscesses, perianal abscesses may require prompt medical treatment, such as an incision and debridement or lancing.
[edit] See also
[edit] References
- ^ Raz R, Miron D, Colodner R, Staler Z, Samara Z, Keness Y (1996). "A 1-year trial of nasal mupirocin in the prevention of recurrent staphylococcal nasal colonization and skin infection.". Arch Intern Med 156 (10): 1109-12. PMID 8638999.
- ^ Watanakunakorn C, Axelson C, Bota B, Stahl C (1995). "Mupirocin ointment with and without chlorhexidine baths in the eradication of Staphylococcus aureus nasal carriage in nursing home residents.". Am J Infect Control 23 (5): 306-9. PMID 8585642.
