Pilonidal cyst

Definition

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.

Description

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 bacteria and the body's immune response are required. In response to the invading bacteria, white blood cells gather at the infected site and begin producing chemicals called enzymes that attack the bacteria by first marking and then digesting it. These enzymes kill the bacteria and break them down into small pieces that can travel in the circulatory system prior to being eliminated from the body. Unfortunately, these chemicals also digest body tissues. In most cases, bacteria produce similar chemicals. The result is a thick, yellow liquid-pus-containing dead bacteria, 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 invading bacteria activate 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, due to 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, commonly, the tissue that is most easily digested. A good example is an abscess just beneath the skin. It most easily continues along immediately beneath the surface rather than traveling up through the outermost layer or down through deeper structures where it could drain its toxic contents. The contents of an abscess can 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 bacteria but by non-living irritants such as drugs. If an injected drug such as penicillin is not absorbed, it stays where it is injected and may cause enough irritation to generate a sterile abscess. Such an abscess is 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 such as Staphylococcus aureus, which is a very common 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 blood stream. Bacteria, amoebae, 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, bacteria that cause pneumonia 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 commonly involved bacteria is Staphylococcus aureus. Acne is a similar condition involving sebaceous glands on the face and back.

• Pilonidal cyst. 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 such as 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 bacteria, 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.

Diagnosis

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 an individual's symptoms and the results of a physical examination do not help, a physician may have to resort to a battery of tests to locate the site of an abscess. 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.

Treatment

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 break down and spontaneous release of pus. This treatment is best reserved for smaller abscesses in less sensitive areas of the body such as limbs, trunk, and 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 an infection from the area.

Prognosis

Once an abscess is properly drained, the prognosis is excellent for the condition itself. The reason for the abscess (other diseases an individual has) will determine the overall outcome. If, on the other hand, an 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.

Health care team roles

First aid providers may unknowingly initiate an abscess by using inappropriate or incorrect techniques. A physician, surgeon, physician's assistant, or nurse practitioner usually diagnoses the presence of an abscess. Radiologists and laboratory personnel may assist in the process of establishing a diagnosis. A physician, surgeon, physician's assistant, or nurse practitioner usually drains an abscess. Nurses provide supportive care, dress the wound, and educate patients about caring for the resulting wound. Occasionally, a physical therapist may be needed to recover lost function.

Prevention

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.

Key Terms

Cellulitis

Inflammation of tissue due to infection.

Enzyme

Any of a number of protein chemicals that can initiate chemical reactions at body temperature.

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. , , 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.