CONDITIONS
Pilonidal Disease
Pilonidal abscess and sinus: symptoms, causes, treatments & FAQs
Pilonidal disease occurs in the cleft between the buttocks (the “natal cleft”), where hair and debris can become trapped under the skin and cause inflammation, infection and sometimes an abscess. It may present as an acute pilonidal abscess (painful swelling and pus) or a chronic pilonidal sinus (small pits/openings with intermittent discharge).
What is pilonidal disease?
“Pilonidal” literally means “nest of hair.” The condition usually occurs at the top of the buttock cleft. It can form a sinus tract (a small tunnel under the skin) and can become infected, leading to an abscess.
Key point: An acute, painful swelling with pus is often an abscess and may need urgent drainage.
HTML diagrams (simple guides)
These simplified diagrams are made with HTML/CSS (no SVG) to illustrate location and typical patterns.
Where pilonidal disease occurs
Acute abscess vs chronic sinus
Symptoms
Acute pilonidal abscess
- Severe pain at the top of the buttock cleft (worse when sitting)
- Swelling or a tender lump, redness and warmth
- Pus discharge (if it drains)
- Fever or feeling unwell (sometimes)
Chronic pilonidal sinus
- Small pits/holes in the cleft
- Intermittent discharge (clear fluid or pus), unpleasant smell
- Recurrent soreness or flare-ups
- Occasional bleeding from irritated tissue
If you have severe pain, fever, rapidly increasing swelling, spreading redness, or you feel very unwell, seek urgent assessment.
What causes pilonidal disease?
Pilonidal disease is thought to occur when hair and debris are pushed into the skin of the natal cleft, causing inflammation and sometimes infection. It is more likely when the cleft is deep and friction/sweating occur.
- Hair, friction and pressure in the natal cleft
- Prolonged sitting, tight clothing, sweating
- Family tendency and body hair
- Young adulthood is a common time for symptoms to appear
Treatments
Acute abscess
Key point: Antibiotics alone often don’t cure an abscess. Drainage is usually the most effective treatment.
- Incision and drainage (often urgent) to release pus and relieve pain
- Antibiotics may be added if there is spreading skin infection or fever, or if immune risk is present
- Dressings/wound care advice and pain relief
Chronic or recurrent disease
If symptoms keep recurring, your surgeon may discuss procedures to remove the sinus tracts and reduce recurrence risk. Options vary by anatomy and surgeon preference.
- Sinus excision (removing pits/tracts) with different closure approaches
- Off-midline closure techniques (often chosen to reduce recurrence in suitable cases)
- Occasionally, staged approaches depending on inflammation and complexity
Aftercare and reducing recurrence
Prevention focus: reduce hair build-up, friction, sweating and pressure in the natal cleft where possible.
- Follow dressing/wound-care instructions and attend follow-up
- Keep the area clean and dry
- Reduce hair in the cleft if advised (trimming/hair removal guidance from your clinician)
- Take breaks from prolonged sitting when possible
- Wear breathable clothing; manage sweating/friction
FAQs
Is pilonidal disease caused by poor hygiene?
No. Hygiene can help reduce irritation, but pilonidal disease is mainly related to hair/debris becoming trapped in the natal cleft and friction/pressure in that area.
Will antibiotics cure a pilonidal abscess?
Antibiotics may help if there is spreading infection or fever, but an abscess usually needs drainage because pus is trapped. Drainage typically relieves pain quickly.
Can pilonidal disease come back after drainage?
Yes. Drainage treats the abscess episode, but a sinus tract can remain. If you have repeated flare-ups, you may benefit from assessment for definitive treatment options.
Does hair removal help?
In some people, reducing hair in the natal cleft can help reduce recurrence risk. Your clinician can advise what method (if any) is suitable for you.