Pilonidal Sinus

Specialist Support
If you require this leaflet in another language, large print or another format, i.e. audiotape, please contact Patient and Customer Services on Freephone 0800 917 6039.

What is Pilonidal Sinus?

• Pilonidal means a 'nest of hairs'
• A sinus tract is a small abnormal channel (a narrow tunnel) in the body

A pilonidal sinus is an infected tract under the skin between the buttocks.  This disease affects 26 per 100,000 people.  Although it is more common in men, it occurs frequently in women as well.  There is an in-drawing of hair follicles (the small structures under the skin that make the hairs) due to the tethering of the skin in the groove between the buttocks (the natal cleft).  This allows hair to enter the follicle and infection to occur although hairs are not always present.

Pilonidal sinus commonly presents as an acute (rapid onset) abscess and requires urgent hospital treatment, usually by surgery to drain the abscess.  However, in the more chronic (persistent) situation, it presents with pain, discharge and/or bleeding.  Patients may have had symptoms of the disease for many years.

Author:  DSU/AS     Produced: Sept 2010     Review: Sept 2012     Ref: DSU/015