The incidence of pilonidal disease is approximately 0.7% in young adults and is commonly accepted to be an acquired condition caused by embedded hairs in the intergluteal cleft . Pilonidal disease may present as an acute abscess, a simple pilonidal cyst, or a complicated or recurrent sinus. Primary midline openings or pits may be seen in the gluteal cleft approximately 5 cm cephalad to the anus . Chronic sinus tracts become lined with squamous epithelium. Recurrence rates vary depending on the study and procedure (Table 25.1). © Springer-Verlag London Limited 2010.