In Latin pilus means hair and nidus means nest. It is commonly an infection in the hips (natal) cleft. This disease consists of a sinus situated a short distance behind the anus between the buttocks which generally contains hairs. Men are more commonly affected than women. Majority are dark hairy subjects. The condition occurs in dark haired white race persons whose hairs are stiffer than the silky blonds.
It occurs in young hairy men who have large buttocks and deep natal cleft. Patients are young have a long sitting occupation. It was so common among jeep drivers in 1935 to 1945 war that it was known as “jeep bottom”
more information on Pilonidal treatment click here