Pilonidal Disease

In pilonidal disease, a lesion called a coccygeal or pilonidal cyst develops in the sacral area. The cyst­which usually contains hair - becomes infected and commonly produces an abscess, a draining sinus, or a fistula. Generally, a pilonidal cyst produces no symptoms until it becomes infected. The incidence is highest among hirsute, white men ages 18 to 30.

Causes

The exact reason why pilonidal disease occurs is still unclear. Possible causes include:

• Some people are born with small holes or pits near the base of the spine. These are in fact enlarged hair follicles, which when subjected to friction and motion, are injured and disrupted so the hair pokes through the wall of the follicle into the surrounding skin setting up a foreign body reaction.
• Neighbouring hairs or free hairs from other parts of the body collect in the pit and invade the small opening created by the distorted hair follicles.
• Skin and perineal bacteria such as Staphylococcus aureus and Bacteroides species invade the opening and cause infection.

Signs and Symptoms

Investigation of the patient's 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.

Diagnostic tests

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

Treatment

Conservative measures consist of incision and drainage of abscesses, regular extraction of protruding hairs, and sitz baths (four to six times per day). However, persistent infections may result in abscess formation and require surgical excision of the infected area.

After excision of a pilonidal abscess, the patient requires regular follow-up care to monitor wound healing. The surgeon may periodically palpate the wound during healing with a cotton-tipped applicator, curette excess granulation tissue, and extract loose hairs to promote wound healing from the inside out and to prevent dead cells from collecting in the wound. Complete healing can take several months.