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.

Dear Dr. Roach • The article about the boy suffering after surgery for three years from a pilonidal cyst really hit home. My son developed a pilonidal cyst in June 2012 and also had a very bad ...

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, ...

DEAR DR. ROACH: I am writing because my son had a pilonidal cyst removed in March of 2010, almost three years ago. For the first six months, I kept the area clean and free of hair. After six months ...