What Is a Perianal Abscess?

A perianal abscess is a localised collection of pus in the tissues around the anus, usually resulting from infection of the small anal glands that normally lubricate the anal canal. When these glands become blocked and infected, pus builds up, causing severe pain and swelling.

Symptoms

  • Severe throbbing pain around the anus, worse with sitting, walking, or bowel movement
  • Visible swelling and redness
  • Warmth over the swollen area
  • Fever and general unwellness
  • Difficulty passing stool due to pain
  • Sometimes discharge if the abscess starts to drain spontaneously

Symptoms usually develop over 1 to 3 days and worsen rapidly.

Causes and Risk Factors

  • Infection of anal glands (most common)
  • Anal fissure with secondary infection
  • Diabetes
  • Immunocompromise (HIV, chemotherapy)
  • Crohn's disease
  • Inflammatory bowel disease
  • Trauma

When to See a Specialist

Immediately, if you have:

  • Severe perianal pain with visible swelling
  • Fever with perianal pain
  • Rapidly worsening pain
  • Discharge from a perianal opening
  • Any of the above with diabetes

Perianal abscess is a condition that should not be delayed. Untreated abscess can spread, cause severe systemic infection, and lead to more complex fistula.

Diagnosis

Diagnosis is usually clinical. Occasionally imaging (ultrasound or MRI) is needed to assess deep or complex abscesses.

Treatment

Incision and Drainage

The primary treatment. A small incision is made under local or short general anaesthesia to drain the pus, followed by dressing and antibiotic cover.

Follow-up Care

Regular dressing changes, oral antibiotics, sitz baths, and pain management. Diabetic control is essential where applicable.

Simultaneous Fistula Management

Because perianal abscess is very often associated with an underlying anal fistula, we assess for fistula at the time of abscess presentation. When both are identified, we treat them simultaneously rather than requiring a separate second procedure later. This reduces the total number of procedures the patient undergoes and shortens overall recovery. About 40 to 50% of perianal abscesses are associated with, or subsequently develop into, anal fistula, so structured follow-up over 6 to 12 weeks is also important where simultaneous treatment is not appropriate.

Recovery

Most patients feel dramatically better within hours of drainage. Full recovery takes 1 to 2 weeks. Return to work is usually possible within a few days depending on job type.

Prevention

  • Manage diabetes carefully
  • Treat anal fissure and other perianal conditions early
  • Maintain good perianal hygiene
  • Address chronic diarrhoea

Related Conditions

Anal Fistula | Recurrent Anal Fistula