Pilonidal disease may develop congenitally from a tendency to hirsutism, or it may be acquired from stretching or irritation of the sacrococcygeal area (intergluteal fold) from prolonged rough exercise (such as horseback riding), heat, excessive perspiration, or constricting clothing.

Pain and discomfort associated with pilonidal disease can cause psychosocial complications for the patient, such as impaired social interaction and difficulty performing work-related activities. This is most likely if his lifestyle or occupation requires vigorous activity that irritates the cyst, causing increased pain.

Investigation of the patient history may turn up one or more predisposing factors for pilonidal disease. Typically, the patient complains of localized pain, tenderness, swelling, and heat over the affected area. He may also describe continuous or intermittent purulent drainage. If the infection is severe enough, signs and symptoms include chills, fever, headache, and malaise.

On inspection, you may detect a series of openings along the midline, with thin,
brown, foul-smelling drainage or a protruding tuft of hair. Palpation of the area may produce purulent drainage if the drainage isn’t already continuous.

Cultures of discharge from the infected cyst may show staphylococci or skin bacteria; the discharge doesn’t usually contain bowel bacteria.