A perianal abscess is a painful collection of pus that forms near the anus, usually when one of the small glands in the area becomes blocked and infected. It tends to come on over a short time and can become very tender, often with swelling and a feeling of being generally unwell. An abscess usually needs to be drained promptly, as it will not clear with antibiotics alone.
What causes a perianal abscess?
Blocked anal glands
The usual starting point, becoming infected
A build-up of pus
Infection collects and forms the abscess
Inflammatory bowel disease
Sometimes linked, particularly Crohn's disease
Lowered resistance to infection
Can make abscesses more likely
Sometimes no clear reason
An abscess can occur without an obvious trigger
When to seek assessment promptly
- Increasing pain and swelling near the anus
- Redness and warmth over the area
- A tender lump close to the opening
- Feeling generally unwell or feverish
- Pain that is worsening rather than settling
How it is treated
An abscess is a collection of pus that generally needs to be drained to relieve the pain and clear the infection, and antibiotics on their own are usually not enough. The main treatment is a procedure to make a small opening and drain the abscess, which often brings rapid relief and is frequently done as a day case. Afterwards, the wound is usually left to heal from the inside out over a few weeks, with simple dressing care that Mr Kimble explains fully. Some abscesses go on to leave a small track, called a fistula, which may need further treatment later, and review helps pick this up.
Seek prompt medical care if you have increasing pain and swelling near the anus, especially with a fever, feeling unwell or difficulty passing urine, as an abscess usually needs timely drainage.