What are pilonidal sinus and cysts?
A pilonidal cyst and sinus can be one or several openings in the skin between the buttocks. Often there is a cyst at the base of the sinus, the passage that leads to an abscess, which is a collection of pus. Most pilonidal sinuses become infected when loose hair and debris collect in them. These cysts most commonly form over the tailbone. Hair and sweat — as well as friction and pressure — may push hair into the skin when your child is sitting. The first sign of a pilonidal cyst may be an abscess. Symptoms include swelling, warmth, redness and tenderness at the site, but cysts may also be present without symptoms until adolescence or early adulthood.
