Anal Abscess Facts
- A perirectal abscess is a collection of pus in the deep tissues surrounding the anus.
- By contrast, a perianal abscess is a shallower collection of pus under the skin surrounding the anus; however, both are sometimes described as an anal abscess.
- Both types of abscesses need immediate medical attention; however, a perirectal abscess usually is the more severe infection.
- A delay in treatment may cause serious worsening of the condition and unnecessary complications.
Anal Abscess Causes
Perirectal and perianal abscesses are thought to develop from the glands surrounding the anus; on occasion, perianal abscesses may develop from infected skin adjacent to the anus. Glands may plug up, usually leading to bacterial infection. When the glands fill with pus, they may burst inward, releasing their infected contents into the spaces around the rectum and anus. This pus causes an abscess, or pus collection, in the spaces surrounding the rectum or anus. The anal abscess may enlarge, causing pain, fever, and difficulty with bowel movements.
Certain people are more likely to develop perirectal and perianal abscesses, including those with the following medical conditions:
- AIDS or HIV infection with low white blood cell counts
- Crohn's disease
- Persons on medications that suppress the body's immune system, such as steroids (prednisone, methylprednisolone), or those undergoing chemotherapy for cancer
- Placement of foreign bodies into the anus
- Sexually transmitted diseases
- anal fissures
When to Seek Medical Care for an Anal Abscess
If a person suspects they have a perirectal or perianal abscess they should see a healthcare professional. The diagnosis is not always easy to make, and the healthcare professional may need to do tests or consult with specialists.
Go to an emergency department when you have any of the following symptoms:
- High fever or shaking chills
- Significant rectal/anal pain
- Inability to have a bowel movement, or a painful bowel movement
- Persistent vomiting
- Any other unusual signs or symptoms that may indicate an emergency condition
Anal Abscess Diagnosis
The healthcare professional will ask questions about the patient's condition. Give the healthcare professional all necessary information. Discussing the details may be embarrassing, but healthcare professionals and other medical personnel are required to maintain confidentiality. Honest responses to the healthcare professional's questions will help provide the patient faster appropriate care.
- The healthcare professional will then examine the patient and should explain the parts of the exam may be uncomfortable and will be careful to protect the patient's modesty.
- The healthcare professional should provide clear answers to any questions the patient asks; they should understand the treatment plan.
- Sometimes the diagnosis is obvious, and no tests are needed. At other times, blood and urine tests and special imaging tests such as X-ray, CT scan, MRI, and ultrasound may be needed. The healthcare professional may also consult other specialists to confirm the diagnosis or to come up with the best treatment plan.
- acetaminophen (Tylenol and others), may help control the pain and fever.
- If the abscess opens by itself there will be a release of pus, and possibly some relief of pain and fever. Regardless, the abscess are still should be examined by a healthcare professional.
- Even if the symptoms improve with home care, the affected individual should seek medical attention. Abscesses need to be evaluated and treated by a healthcare professional. They rarely resolve on their own. Many people need further special treatment, especially with perirectal abscesses, to avoid complications or a return of the abscess.
Anal Abscess Medical Treatment
Depending upon the severity of the abscess and any other medical problems, treatment may be accomplished on an outpatient or inpatient basis. The treatment plan should be explained to the patient in detail.
- Minor surgery may be performed in the healthcare professional's office or in the emergency department using local anesthesia (an injection in the infected area), and possibly IV sedation. Most patients are referred to a surgeon for treatment of perirectal abscesses because the abscess may involve additional structures or require more debridement that may not be apparent until it is surgically explored. Patients should be able to go home when they awake and will be given prescription pain medication for the first few days with some uncomplicated abscesses.
- Alternatively, the surgery may be done in the operating room by a surgeon using spinal anesthesia (the patient is awake and numb from the waist down) or general anesthesia (patient is "asleep" under sedation). The hospital stay may be overnight or several days.
- Admission to the hospital may be required with an IV line for fluids, antibiotics, and pain medicine.
- Patients may need an update of their tetanus booster, if this has not been done in the past 5-10 years.
- Blood and other tests may need to be repeated to evaluate the patient's progress after treatment.
Anal Abscess Follow-up
Patients may have pain for several days following surgery, but should improve over time.
- Patients may not have stitches. Infected wounds such as abscesses are left open to drain. If they were stitched shut they would just fill with pus again. There may be packing left in the wound, which usually will be removed by the healthcare professional after a few days.
- Patients may need to take an antibiotic and pain medication for several days, depending on their condition.
- Using stool softeners and adhering to good hygiene, such as sitz baths after every bowel movement, decreases the patient's discomfort and helps recovery.
Medically reviewed by Joseph Palermo, DO; American Osteopathic Board Certified Internal Medicine
MedscapeReference.com. Perirectal Abscess.
PubMed Health.gov. Anorectal Abscess.