Pilonidal Disease

Also known as: pilonidal cyst, pilonidal sinus, PNS.

What is pilonidal disease?

Pilonidal disease is one or more skin openings between the top of the cheeks of the buttocks. A pilonidal sinus is a small tunnel in the skin which may fill with fluid. It is also known as a pilonidal cyst when containing hair, dirt and skin debris or a pilonidal abscess when infected with bloody secretions. It’s more common in adult men, though it can occur particularly in hairy adolescents.

What causes pilonidal disease?

Friction and pressure from prolonged sitting, pushing hair and sweat into the skin with sinus/cyst formation which, when becoming infected, causes one or more abscesses to form. A family history of PNS and obesity may be contributing factors.

What are the symptoms of pilonidal disease?

Symptoms can range in severity from a small symptomless dimple to a large, painful mass. Swelling, redness, tenderness, fluid drainage, fever and nausea may occur.

What are pilonidal disease care options?

Minor abscesses can be surgically drained. More severe or recurring problems may require surgical removal of the cyst and surrounding tissues.

Reviewed by: Ana Margarita Duarte, MD

This page was last updated on: September 16, 2025 12:29 PM