Perianal abscess
Encyclopedia
Anorectal abscess is an abscess
adjacent to the anus
. It arises from an infection at one of the anal crypts of Morgagni
which leads to inflammation and abscess formation. Most cases of perianal abscesses are sporadic, though there are certain situations which elevate the risk for developing the disease, such as diabetes mellitus
, Crohn's disease
, chronic steroid treatment and others. Ischiorectal, inter- and intrasphincteric abscesses have been described.
, drainage from the rectum, fever
and chills, or a palpable mass near the anus.
The condition invariably becomes extremely painful, and usually worsens over the course of just a few days. The pain may be limited and sporadic at first, but invariably worsens to a constant pain which can become very severe when body position is changed (e.g., when standing up, rolling over, and so forth). Depending upon the exact location of the abscess, there can also be excruciating pain during bowel movements, though this is not always the case. This condition may occur in isolation, but is frequently indicative of another underlying disorder, such as Crohn's disease
.
s, since this is almost always the cause of any sudden anal discomfort. The presence of the abscess, however, is to be suspected when the pain quickly worsens over one or two days and the usual hemorrhoid treatments are ineffective in bringing relief. Furthermore, any serious abscess will eventually begin to cause signs and symptoms of general infection, including fever
and nighttime chills.
A physician can rule out a hemorrhoid with a simple visual inspection, and usually appreciate an abscess by touch.
Historically, many rectal abscesses are caused by bacteria common in the digestive system, such as E. coli. While this still continues often to be the case, there has recently been an uptick in the causative organism being staphylococcus
, as well as the difficult to treat community-acquired methicillin-resistant S. aureus. Because of the increasing appearance of more exotic bacteria in anal abscesses, microbiological examination will always be performed on the surgical exudate to determine the proper course of any antibiotic treatment.
, but it is highly preferred to be formally admitted to a hospital and to have the surgery performed in an operating room under general anesthesia.
Generally speaking, a fairly small but deep incision is performed close to the root of the abscess. The surgeon will allow the abscess to drain its exudate and attempt to discover any other related lesions in the area. This is one of the most basic types of surgery, and is usually performed in less than thirty minutes by the anal surgical team. Generally, a portion of the exudate is sent for microbiological analysis to determine the type of infecting bacteria. The incision is not closed (stitched), as the damaged tissues must heal from the inside toward the skin over a period of time.
The patient is often sent home within twenty-four hours of the surgery, and may be instructed to perform several 'sitz bath
s' per day, whereby a small basin (which usually fits over a toilet) is filled with warm water (and possibly, salts) and the affected area is soaked for a period of time. Another method of recovery involves the use of surgical packing, which is initially inserted by the surgical team, with redressing generally performed by hospital staff or a District Nurse. During the week following the surgery, many patients will have some form of antibiotic therapy, along with some form of pain management therapy, consistent with the nature of the abscess.
The patient usually experiences an almost complete relief of the severe pain associated to his/her abscess upon waking from anesthesia; the pain associated with the opening and draining incision during the post-operative period is often mild in comparison. In many cases, the patient is completely healed with no discomfort whatsoever within just one or two weeks of the surgery.
will almost certainly form, connecting the rectum to the skin. This requires more intensive surgery. Furthermore, any untreated abscess may (and most likely will) continue to expand, eventually becoming a serious systemic infection.
Abscess
An abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...
adjacent to the anus
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
. It arises from an infection at one of the anal crypts of Morgagni
Lacunae of Morgagni
Lacunae of Morgagni, also called the urethral lacunae of the male urethra , are small depressions or recesses on the surface of the mucous membrane of the urethra. Their openings are usually directed distally...
which leads to inflammation and abscess formation. Most cases of perianal abscesses are sporadic, though there are certain situations which elevate the risk for developing the disease, such as diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
, Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
, chronic steroid treatment and others. Ischiorectal, inter- and intrasphincteric abscesses have been described.
Classification
There are four types of anorectal abscesses perianal, ischiorectal, intersphincteric, and supralevator.Signs and symptoms
Pain in the perianal area is the most common symptom of an anorectal abscess. The pain may be dull, aching, or throbbing. It is worst when the person sits down and right before a bowel movement. After the individual has a bowel movement, the pain usually lessens. Other signs and symptoms of anorectal abscess include constipationConstipation
Constipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...
, drainage from the rectum, fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
and chills, or a palpable mass near the anus.
The condition invariably becomes extremely painful, and usually worsens over the course of just a few days. The pain may be limited and sporadic at first, but invariably worsens to a constant pain which can become very severe when body position is changed (e.g., when standing up, rolling over, and so forth). Depending upon the exact location of the abscess, there can also be excruciating pain during bowel movements, though this is not always the case. This condition may occur in isolation, but is frequently indicative of another underlying disorder, such as Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
.
Differential diagnosis
This condition is often misdiagnosed initially by the patient as a bad case of hemorrhoidHemorrhoid
Hemorrhoids or haemorrhoids , are vascular structures in the anal canal which help with stool control. They become pathological or piles when swollen or inflamed. In their physiological state they act as a cushion composed of arterio-venous channels and connective tissue that aid the passage of...
s, since this is almost always the cause of any sudden anal discomfort. The presence of the abscess, however, is to be suspected when the pain quickly worsens over one or two days and the usual hemorrhoid treatments are ineffective in bringing relief. Furthermore, any serious abscess will eventually begin to cause signs and symptoms of general infection, including fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
and nighttime chills.
A physician can rule out a hemorrhoid with a simple visual inspection, and usually appreciate an abscess by touch.
Cause
Abscesses are caused by a high density infection of (usually) common bacteria which collect in one place or another for any variety of reasons. Anal abscesses, without treatment, are likely to spread and affect other parts of the body, particularly the groin and rectal lumen. All abscesses can progress to serious generalized infections requiring lengthy hospitalizations if not treated.Historically, many rectal abscesses are caused by bacteria common in the digestive system, such as E. coli. While this still continues often to be the case, there has recently been an uptick in the causative organism being staphylococcus
Staphylococcus
Staphylococcus is a genus of Gram-positive bacteria. Under the microscope they appear round , and form in grape-like clusters....
, as well as the difficult to treat community-acquired methicillin-resistant S. aureus. Because of the increasing appearance of more exotic bacteria in anal abscesses, microbiological examination will always be performed on the surgical exudate to determine the proper course of any antibiotic treatment.
Diagnostic approach
Diagnosis of anorectal abscess begins with a medical history and physical exam. Imaging studies which can help determine the diagnosis in cases of a deep non-palpable perirectal abscess include pelvic CT scan, MRI or trans-rectal ultrasound. These studies are not necessary, though, in cases which the diagnosis can be made upon physical exam.Treatment
Anal abscesses, unfortunately, cannot be treated by a simple course of antibiotics or other medications. Even small abscesses will need the attention of a surgeon immediately. Treatment is possible in an emergency room under local anesthesiaLocal anesthesia
Local anesthesia is any technique to induce the absence of sensation in part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with...
, but it is highly preferred to be formally admitted to a hospital and to have the surgery performed in an operating room under general anesthesia.
Generally speaking, a fairly small but deep incision is performed close to the root of the abscess. The surgeon will allow the abscess to drain its exudate and attempt to discover any other related lesions in the area. This is one of the most basic types of surgery, and is usually performed in less than thirty minutes by the anal surgical team. Generally, a portion of the exudate is sent for microbiological analysis to determine the type of infecting bacteria. The incision is not closed (stitched), as the damaged tissues must heal from the inside toward the skin over a period of time.
The patient is often sent home within twenty-four hours of the surgery, and may be instructed to perform several 'sitz bath
Sitz bath
A sitz bath is a bath in which a person sits in water up to the hips. It is used to relieve discomfort and pain in the lower part of the body, for example, due to hemorrhoids , anal fissures, rectal surgery, an episiotomy, uterine cramps, inflammatory bowel disease, and infections of the bladder,...
s' per day, whereby a small basin (which usually fits over a toilet) is filled with warm water (and possibly, salts) and the affected area is soaked for a period of time. Another method of recovery involves the use of surgical packing, which is initially inserted by the surgical team, with redressing generally performed by hospital staff or a District Nurse. During the week following the surgery, many patients will have some form of antibiotic therapy, along with some form of pain management therapy, consistent with the nature of the abscess.
The patient usually experiences an almost complete relief of the severe pain associated to his/her abscess upon waking from anesthesia; the pain associated with the opening and draining incision during the post-operative period is often mild in comparison. In many cases, the patient is completely healed with no discomfort whatsoever within just one or two weeks of the surgery.
Complications
If left untreated, an anal fistulaAnal fistula
Anal fistula, or fistula-in-ano, is an abnormal connection between the epithelialised surface of the anal canal and the perianal skin....
will almost certainly form, connecting the rectum to the skin. This requires more intensive surgery. Furthermore, any untreated abscess may (and most likely will) continue to expand, eventually becoming a serious systemic infection.