Pilonidal disease may involve three common occurrences:

• Acute Abscess Formation: an abscess formation between the buttocks. Treatment may include simple incision and drainage.

• Simple Sinus: Approximately 50% of patients who have a resolved abscess develop a pilonidal sinus.

• Complex or recurrent disease: A small number of patients with a resolved pilonidal sinus go on to develop complex or recurrent pilonidal disease. Patients suffering from recurrent pilonidal disease have persistent, non-healing wounds which require repeated treatment.