ABSCESS

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 draws huge amounts of white blood cells to the area and 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 preexisting rather than a newly formed anatomical cavity.

Contents

Manifestations

Treatment

Antibiotics

Incision and drainage

Primary closure

Recurrent infections

Perianal abscess

See also

References

External links

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.

Treatment

Antibiotics

As ''Staphylococcus aureus'' bacteria is a common cause, an anti-Staphylococcus antibiotic such as Flucloxacillin or dicloxacillin is used. With the emergence of community-acquired methicillin-resistant Staphylococcus aureus MRSA, these traditional antibiotics may be ineffective; alternative antibiotics effective against community-acquired MRSA often include clindamycin, trimethoprim-sulfamethoxazole, and doxycycline. (However, if cellulitis rather than abscess, consideration should be given to possibility of strep species as cause that are still sensitive to traditional anti-Staphylococcus agents such as dicloxacillin or cephalexin.)It is important to note that antibiotic therapy alone ''without surgical drainage of the abscess'' is seldom effective due to antibiotics often being unable to get into the abscess and their ineffectiveness at low pHs.

Incision and drainage

Main articles: Incision and drainage

The abscess should be inspected to identify if foreign objects are a cause, requiring surgical removal. If foreign objects are not the cause, a doctor will incise and drain the abscess and prescribe painkillers and possibly antibiotics.
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''.
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.

Primary closure

Primary closure has been successful when combined with curettage and antibiotics^[1] or with curettage alone.^[2] However, another randomized controlled trial found primary closure led to 35% failing to heal primarily and primary closure longer median number of days to closure (8.9 versus 7.8).^[3]
In anorectal abscesses, primary closure healed faster, but 25% of abscesses healed by secondary healing and recurrence was higher.^[4]

Recurrent infections

Recurrent abscesses are often caused by community-acquired MRSA. While resistant to most beta lactam antibiotics commonly used for skin infections, it remains sensitive to alternative antibiotics, ie clindamycin (Cleocin), trimethoprim-sulfamethoxazole (Bactrim), and doxycycline (unlike hospital-acquired MRSA that may only be sensitive to vancomycin IV).
For recurrent infections due to [''Staphylococcus''], consider the following measures:

★ Topical mupirocin applied to the nares A 1-year trial of nasal mupirocin in the prevention of recurrent staphylococcal nasal colonization and skin infection., Raz R, Miron D, Colodner R, Staler Z, Samara Z, Keness Y, , , Arch Intern Med, 1996 . In this randomized controlled trial, patients used nasal mupirocin twice daily 5 days a month for 1 year.

★ Chlorhexidine baths Mupirocin ointment with and without chlorhexidine baths in the eradication of Staphylococcus aureus nasal carriage in nursing home residents., Watanakunakorn C, Axelson C, Bota B, Stahl C, , , Am J Infect Control, 1995 , 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.

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.

See also

★ Sterile abscess

★ Head and neck anatomy

★ Tooth abscess

References

1. Open versus closed surgical treatment of abscesses: a controlled clinical trial, Abraham N, Doudle M, Carson P, , , The Australian and New Zealand journal of surgery, 1997
2. Treatment of acute abscesses by incision, curettage and primary suture without antibiotics: a controlled clinical trial, Stewart MP, Laing MR, Krukowski ZH, , , The British journal of surgery, 1985
3. Treatment of acute abscesses in the casualty department, Simms MH, Curran F, Johnson RA, ''et al'', , , British medical journal (Clinical research ed.), 1982
4. Incision and drainage v. incision, curettage and suture under antibiotic cover in anorectal abscess. A randomized study with 3-year follow-up, Kronborg O, Olsen H, , , Acta Chirurgica Scandinavica, 1984

External links

★ MedlinePlus Medical Encyclopedia - Abscess

★ MedlinePlus Medical Encyclopedia - Skin Abscess