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, ...

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 ...

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.

This procedure works well for a pilonidal sinus and there are no serious concerns about its safety. A pilonidal sinus is a small infected cavity under the skin between the buttocks, just above the ...

From the Department of Surgery, Peter Bent Brigham Hospital, Boston, Massachusetts. Glenn — On staff of the New York Hospital, New York City. For record and address of author see "This Week's Issue," ...