What causes a pilonidal sinus?
Hair and friction
Loose hairs work into the skin and create small tracts.
Prolonged sitting
Pressure and sweating in the area contribute.
Body hair
More hair in the natal cleft increases the risk.
Blocked tracts
Debris trapped in the tunnels can become infected.
Not poor hygiene
It is not caused by being unclean, though good skin care helps control it.
When to seek assessment promptly
- A painful, swelling lump at the top of the buttock cleft
- Discharge of blood or pus from an opening in the skin
- Flare-ups that keep returning
- Symptoms that interfere with sitting, work or daily life
- Any sign of spreading infection or a fever
How it is treated
If there is an active abscess, the first step is usually to drain it to relieve pain and clear infection. For the sinus itself, Mr Kimble discusses the most suitable definitive option, which may range from minimally invasive techniques that target the tracts through small openings, to excision, or a flap procedure for more extensive or recurrent disease. Recovery depends on the procedure: some wounds heal quickly, while others are managed open over a few weeks with simple dressing changes. Keeping the area clean and reducing hair, for example with regular hair removal, helps lower the chance of it returning. It is important to stop smoking to improve the outcome of any intervention.
If the area becomes very painful, red and swollen, or you develop a fever and feel generally unwell, seek medical advice promptly, as an abscess may need urgent drainage.