The incidence of pilonidal disease is highest in white males (3:1 male:female ratio) between ages 15 and 40, with a peak incidence between 16 and 20 years. It rarely occurs in patients more than 50 years old. It was once thought that pilonidal disease was a congenital condition that developed along an epithelialized tract of the natal cleft.
Patients with pilonidal disease may present with small midline pits or abscesses on or off the midline near the coccyx or sacrum. The patients are generally heavy hirsute males who perspire profusely. The workup is limited to a physical examination unless one suspects Crohn’s disease, in which case an extensive evaluation may be necessary. Physical examination may reveal a spectrum of disease from acute suppuration and an undrained abscess or chronic draining sinuses with multiple mature tracts with hairs protruding from the pit-like openings.
The differential diagnosis includes cryptoglandular abscess-fistulous disease of the anus, hidradenitis suppurativa, furuncle, and actinomycosis.
Untreated pilonidal disease may result in multiple draining sinuses with chronic recurrent abscess, drainage, soiling of clothing, and, rarely, necrotizing wound infections or malignant degeneration.
Treatment of Pilonidal Disease
Pilonidal abscesses may be drained under local anesthesia. A probe may be inserted into the primary opening and the abscess unroofed. Granulation tissue and inspissated hair are pulled out, but definitive therapy is not required at the first procedure. Cure rates of 60–80% have been reported after primary unroofing and extraction of hair. For those that fail to heal after 3 months or develop a chronic draining sinus, definitive therapy may be considered.
Nonoperative therapy with meticulous skin care (shaving of the natal cleft, perineal hygiene) and drainage of abscesses will substantially reduce the need for surgery.
Conservative excision of midline pits with removal of hair from lateral tracts and postoperative weekly shaving has a 90% success rate. Excision with open packing or primary closure have all been advocated. Either open packing or marsupialization leaves the patient with painful wounds slow to heal Closure over suction drainage or the use of lateral incisions with excision of the tracts decreases the rate of wound dehiscence.
The prognosis after surgery is excellent. Recurrent or persistent disease has been reported to be 0–15% and is likely due to inadequate excision where external openings or occult tracts are missed. Inadequate postoperative hygiene with ingrowth of hair into the wound also leads to recurrence.