Pilonidal Sinus

Pilonidal Sinus

A pilonidal sinus is a common surgical condition related to hair.

It most commonly occurs in the natal cleft area (between the buttocks) in the lower back. However, it can also occur between the fingers (of barbers / hair-dressers) or in the umbilicus.

It is usually caused by hair burrowing into the skin at the bottom of the natal cleft area. The theory is that the natal cleft area gets sweaty with excessive sitting (eg. driving / sitting hours playing computer games). This allows the hair to burrow in and become fully under the skin. This eventually causes an infection which can burst out to the side of the natal cleft resulting in an abscess and what is called a secondary fistula.

Pilonidal sinus may present with:

  • Infection – typically an abscess causing pain. This usually requires surgical incision and drainage but can sometimes settle with antibiotics.
  • Chronic discharge – this suggests ongoing chronic infection and requires a definitive procedure. The options are simple excision, marsupialization, endoscopic surgery or flap repair (see Pilonidal Surgery).
  • Incidental midline sinuses in the natal cleft without pain or discharge – This does not require treatment. However, laser hair removal or waxing the area is advisable to prevent more hair burrowing in.