||This article needs additional citations for verification. (April 2008)|
|Classification and external resources|
Carbuncle on buttock of a diabetic patient
A carbuncle (pron.: // or pron.: //) is an abscess larger than a boil, usually with one or more openings draining pus onto the skin. It is usually caused by bacterial infection, most commonly Staphylococcus aureus, or Streptococcus pyogenes, which can turn lethal. However, the presence of carbuncles is actually a sign that the immune system is working. The infection is contagious and may spread to other areas of the body, or other people; those living in the same residence may develop carbuncles at the same time.
Often, the initial cause of a carbuncle cannot be determined. Triggers that make carbuncle infections more likely include rashes such as folliculitis, friction from clothing or shaving, having the hair pulled out, such as sites where clothing or furniture grab at hairs, generally poor hygiene, poor nutrition or weakening of immunity. Poor nutrition may be an important factor. For example, persons with diabetes and immune system diseases are more likely to develop infections (especially bacterial infections of the leg or foot).
A carbuncle is made up of several skin boils. The infected mass is filled with fluid, pus and dead tissue. Fluid may drain out of the carbuncle, but sometimes the mass is so deep that it cannot drain on its own. Carbuncles may develop anywhere, but they are most common on the back and the nape of the neck.
The carbuncle may be the size of a pea or as large as a golf ball. It may be red and irritated, and might hurt when touched. It may also grow very fast and have a white or yellow center. It may crust or spread to other skin areas. Sometimes other symptoms may occur, such as fatigue, fever and a general discomfort or sick feeling. Itching may occur before the carbuncle develops.
The word is believed to have originated from the Latin: carbunculus, originally a small coal; diminutive of carbon-, carbo: charcoal or ember, but also a carbuncle stone, "precious stones of a red or fiery colour", usually garnets.
Oral antibiotics against the gram positive bacteria is recommended when the boil is larger than 5 cm diameter, or 2 cm proud (tall), or very painful, or appearing to (or actually is) spread to new sites, or entered below the skin into underlying structure, such as causing a painful muscle, bone, ligament or joint, or if the lymph nodes are inflamed. Oral antibiotics will treat the carbuncle and antibiotics should be continued until the carbuncle has healed over.
Streptococcus pyogenes in the blood stream is noted as a common cause of rheumatic fever (and hence arthritis), and also heart valve failure, so waiting for a natural cure is not recommended. Any bacterial infection serious enough to cause a large boil can, rarely, lead to blood poisoning or spread to other organs (eg. joints, lungs, brain), and in fact any other body part.
Without antibiotic treatment, carbuncles usually must drain before they will heal.
If left untreated, within two weeks the skin weakens and perforates and the contents explode out, this apparently being caused by the immune system ramping up its repulsion of the bacteria.
Placing a warm moist cloth on the carbuncle and soaking the affected area several times each day helps it to drain, which speeds healing. Squeezing the carbuncle, or cutting it open without medical supervision (and without oral antibiotics effective against the gram positive bacteria) can spread and worsen the infection.
Treatment is certainly needed if the carbuncle lasts longer than two weeks, returns frequently, is located on the spine or the middle of the face, or occurs along with a fever or other symptoms. Treatment helps reduce complications related to an infection. A doctor may prescribe antibacterial soaps, as a preventative for the future, and antibiotics applied to the skin or taken by mouth. Deep or large lesions may need to be drained by a health professional. Proper excision by cruciate incision under strict aseptic conditions will usually treat the condition effectively, but the modern practice is to use antibiotics.
Proper hygiene is very important to prevent the spread of infection. Hands should always be washed thoroughly, preferably with antibacterial soap, after touching a carbuncle. Washcloths and towels should not be shared or reused. Clothing, washcloths, towels, and sheets or other items that contact infected areas should be washed in very hot (preferably boiling) water. Bandages should be changed frequently and thrown away in a tightly-closed bag. If boils/carbuncles recur frequently, daily use of an antibacterial soap or cleanser containing triclosan, triclocarban or chlorhexidine, can suppress staph bacteria on the skin.
The bacteria may not remain inside the boil or carbuncle; it may progress to inside the skin, into underlying tissues. This may occur more often where the boil is on the buttocks or back or upper arm, where the patient may squash the boil and cause the fluids inside to explode their cyst-like containment. This may lead to further boils and carbuncles (or arms, like a mountain ridge branching off existing sites); cellulitis (where the skin appears to be covering infected flesh); infected lymph nodes (which are sore to the touch) and, in fact, infection of any other body part; and the infection causes the person to feel nauseated, fevered, dizzy, weak, lethargic, breathless, unhealthy of the heart, headaches, or (in the worst case) death.
Related and derived terms 
Monstrous carbuncle 
In 1984 Charles, Prince of Wales famously described the proposed Sainsbury Wing extension to the National Gallery in London as a "monstrous carbuncle on the face of a much-loved and elegant friend", a term now widely used to describe architecture, particularly modernist architecture, unsympathetic to its surroundings.
- "Carbuncle - PubMed Health". National Institute of Health. 2007-04-12. Retrieved 2011-05-10.
- OED, "Carbuncle": 1) stone, 3) medical
- "A speech by HRH The Prince of Wales at the 150th anniversary of the Royal Institute of British Architects (RIBA), Royal Gala Evening at Hampton Court Palace". Retrieved 2007-06-16.
- "Prince's new architecture blast". BBC News. 2005-02-21. Retrieved 2007-06-16.
- "No cash for 'highest slum'". BBC News. 2001-02-09. Retrieved 2007-06-16.