What is Perianal Abscess?
Perianal abscesses are the most frequently occurring type of abscesses around the rectum or anus. These abscesses can cause a lot of discomfort. They are found near the edge of the anus and if not treated, can spread into spaces near the rectum or between the muscles closing the anus, as these areas are connected with the vicinity of the anus. Also, they can cause body-wide infections if not addressed.
What Causes Perianal Abscess?
Anorectal abscesses, which are infections that occur near the rectum or anus, are primarily caused by blockages in the small glands found in this area. This makes up about 90% of these types of infections. A perianal abscess is a specific kind of anorectal abscess that is located just around the anus.
There are other things that can cause these infections too, including inflammatory bowel diseases like Crohn’s disease, injury to the area, or even cancer. If someone has repeated or complicated abscesses in this area, it’s important to check for the possibility of Crohn’s disease.
Risk Factors and Frequency for Perianal Abscess
The number of people who get perianal and anorectal abscesses is probably higher than we think. This is because many people either don’t go to the doctor, or they are wrongly thought to have hemorrhoids instead. Generally, those affected are around 40 years old. Adult men are two times more likely to develop an abscess than women. Some things increase the risk of getting an abscess. These include engaging in activities that weaken the immune system or hinder the healing of wounds like smoking, having conditions such as HIV, using drugs that suppress the immune system, and having diabetes. People with Crohn’s disease also have a higher risk of developing a perirectal abscess.
- Perianal and anorectal abscesses are likely more common than believed, due to misdiagnosis or lack of medical attention.
- The average age of people developing an abscess is 40.
- Males are twice likely than females to develop an abscess.
- Activities that weaken the immune system or prevent wounds from healing properly, such as smoking and having HIV, increase the risk of developing an abscess.
- People who use drugs that suppress the immune system or have diabetes are also at higher risk.
- Crohn’s disease is a known risk factor for developing a perirectal abscess.
Signs and Symptoms of Perianal Abscess
When diagnosing a patient, a thorough history and physical examination is often all that’s needed. This includes patients complaining of pain in the anal area, which could feel dull, sharp, aching, or throbbing. They may also show symptoms such as fever, chills, constipation, or diarrhea. More specifically, patients with a perianal abscess may experience constant pain around the anus, which could either be related or unrelated to bowel movements. If the abscess has started draining on its own, patients may report a pus-like discharge or even blood.
A physical exam is usually sufficient to differentiate between other causes of anal pain, such as hemorrhoids. This exam can help identify areas of pus accumulation or redness and swelling in the skin around the anal area. If the inflammation and redness extend beyond the involved area, this is a sign of skin infection, which should be documented. For ongoing care considerations, keep a record if the patient has diabetes and monitor their blood sugar levels regularly through fingerstick tests.
Testing for Perianal Abscess
In most cases, your doctor can diagnose you through a simple physical check-up. They might do a rectal exam, during which they could find a soft mass. Sometimes, the infection could spread beyond this mass and should be noted. If the usual signs are not present but your doctor is still suspicious, especially if you’re experiencing severe, unexplained pain in the anus or rectum, or if your immune system is compromised, they may use imaging methods like CT scans or MRIs. In this case, an MRI is the preferred method because a CT scan might not pick up small abscesses, especially if your immune system is weakened.
They might also use an ultrasound of the anus and rectum, but this is sometimes difficult because of the pain. Your doctor may also conduct a blood test. Usually, people with an abscess, which is a pocket of pus in your body, have a higher than normal white blood cell count. But even if you don’t have that, your doctor might still choose to treat you for an abscess, typically with a surgical procedure to drain the pus.
Treatment Options for Perianal Abscess
If you have an abscess near the anus, also known as a perianal abscess, it’s important to have it drained as soon as possible. Simply taking antibiotics will not be enough to treat it. However, if you have certain health conditions like a heart valve disease, if your immune system is weakened, if you have diabetes, or if you have a severe infection spread throughout your body (sepsis), antibiotics may be necessary after the abscess has been drained. Antibiotics may also be needed if the abscess has caused a widespread skin infection or other signs of a systemic infection.
Doctors typically drain perianal abscesses in a clinic or emergency department. They numb the area around the abscess with a local anesthetic, such as 1% lidocaine, before making an incision (cut) to drain the pus from the abscess. This incision is made as close to the anus as possible to help reduce the chance of a fistula, or a tunnel, forming between the inside of your body and the skin. The doctor then uses gentle probing to make sure no other connected abscesses have been missed. Once they’re certain they’ve drained everything, they may cut away a tiny flap of skin from the incision or the tips of the skin flaps to make sure the abscess drains completely and to discourage the skin from healing too quickly and trapping any remaining pus. If necessary, they help control bleeding by packing the wound. Then, the packing may be left in the wound to encourage it to heal slowly, which can minimize scarring.
Patients are advised to keep the area clean after the procedure. Soaking in a warm tub or using a sitz bath may also provide some pain relief.
If the abscess is particularly large, it may need to be drained in an operating room under anesthesia. This allows your healthcare provider to thoroughly inspect for and treat any other related conditions, such as anal fistula, a small tunnel that can develop between the end of the bowel and the skin near the anus.
What else can Perianal Abscess be?
When dealing with a perianal abscess, doctors will consider several other conditions that may cause similar symptoms. These conditions include:
- Trauma to the anal area
- Anal fissure (a small tear in the lining of the anus)
- Anal fistula (an abnormal connection between the surface of the skin near the anus and the inside of the anus)
- Thrombosed external hemorrhoid (a blood clot in an external hemorrhoid)
- Pilonidal cyst (a cyst or abscess near or on the natal cleft of the buttocks)
- Buttocks abscess
- Cellulitis (a skin infection)
- Crohn’s disease (a type of inflammatory bowel disease)
- Ulcerative colitis (a chronic disease of the large intestine)
- Cancer
- Proctitis (inflammation of the lining of the rectum)
- HIV/AIDS
- Other sexually transmitted diseases
- Bartholin’s abscess (an abscess that affects a gland which lubricates the vagina)
- Hidradenitis suppurativa(a long-term skin condition that features small, painful lumps under the skin).
Each of these conditions could cause similar symptoms to a perianal abscess, so it’s vital to undergo a thorough medical examination to reach an accurate diagnosis.
What to expect with Perianal Abscess
When treated promptly and appropriately, a perirectal abscess – an accumulation of pus in the tissue surrounding the rectum – typically has a very low mortality rate. However, in certain groups of patients such as those with weakened immune systems or Crohn’s disease, or cases where the abscess has been detected late, the risk of death can be higher. This is especially the case if the abscess progresses to a severe and life-threatening condition like Fournier’s gangrene, which is a type of tissue death in the genital area.
Moreover, even in patients who are otherwise healthy, the abscess can lead to significant complications. Specifically, about one-third of patients may develop a fistula – an abnormal connection between two body parts – due to the disease itself or as a result of the procedure to drain the abscess.
Possible Complications When Diagnosed with Perianal Abscess
- Widespread infection throughout the body (sepsis)
- Repeated pocket of infection filled with pus (recurrent abscess)
- An abnormal connection between organs or blood vessels (fistula formation) which can occur due to the disease itself or the surgical treatment
- Loss of ability to control bowel movements (fecal incontinence) due to the disease or its surgical treatment
Recovery from Perianal Abscess
Following treatment, the patient will need measures to control pain, and may require laxatives or fiber supplements to prevent constipation. They will also need to know how to correctly use a sitz bath. A sitz bath is a warm, shallow bath that cleanses the area between the rectum and the vulva or scrotum.
Antibiotics given at home are not typically needed, but might be considered if the patient starts showing symptoms of a whole body infection, like fever or a high white blood cell count.
Since there’s a high chance the condition will return, it’s important for all patients to continue with follow-up care until complete healing has occurred; this can take up to 8 weeks. Additionally, a third of patients may either already have an anal fistula or develop one after their abscess. An anal fistula is a small tunnel that runs from the end of the bowel to the skin near the anus, which is another reason to have regular follow-up care.
If there is a return of the abscess, the patient needs more checks to rule out potential underlying conditions like Crohn’s Disease, HIV, cancer, or others.
Preventing Perianal Abscess
Preventing a perianal abscess, which is a painful collection of pus near the anus, can be a bit challenging, especially if you’re generally healthy. However, one thing that may help is keeping the area around your anus clean and dried, to prevent the skin from cracking. Consuming a diet high in fiber might also theoretically lessen the likelihood of blockages in the anal glands, which can lead to an abscess, though there’s no strong scientific proof to back it up. For patients living with conditions like Crohn’s disease or HIV, managing these health issues well could potentially cut down their risk of getting a perianal abscess.
