A pilonidal sinus is a small tunnel that develops at the top of the crease in the buttocks. Trapped hair around the buttocks crease can lead to an abscess, and a pilonidal sinus may develop as a ...

According to the American Society of Colon and Rectal Surgeons, Pilonidal disease is a chronic skin infection that affects ...

Pilonidal sinus—also called a pilonidal cyst—is a skin infection that occurs in or around the crease of your buttocks. This condition happens when hair, skin cells, and dirt clog a hair follicle, ...

Also known as a pilonidal cyst, the condition forms when a sac of tissue fills with air or fluid in the crease of your buttocks. Pilonidal cyst, doctors say, is mostly caused by a skin infection.