Pilonidal Disease of the Anterior Perineum: An Unusual Presentation and Review of Current Practice Guidelines

Pilonidal disease is a chronic skin condition generally involving trapped hair follicles in the gluteal cleft that leads to irritation and abscess formation. Each year, more than 70 000 cases are reported annually in the United States alone, with most of these cases involving the presacral and gluteal regions. The condition predominantly affects men of all ages but generally decreases in incidence after the age of 25.^1-4 While the pathogenesis is not completely understood, some reports support an embryologic source; however, the more supported theory is acquired disease from natal cleft hair follicles. These follicles insert themselves into the natal cleft, leading to a foreign body reaction, inflammation, and ultimate abscess formation, which may be acute or chronic in nature. Ideal treatment provides patients with curative resolution with repair and return to activities of daily living.^1,5 In the acute setting of an abscess, incision and drainage of the abscess off midline is typically performed; however, with more extensive chronic disease, wide en-bloc excision is recommended with or without immediate reconstruction.^1-2,5 Not often described is extensive pilonidal disease extending beyond the presacral region into the anterior perineum. Current practice guidelines for treatment of such rare presentations is scarce, but incision and drainage of abscesses can also be carried out in these cases. Fistulectomies have been described as well, although wide en-bloc excision techniques have not been well studied. This report presents the case of a 20-year-old man with recurrent pilonidal disease and incidental findings of several pilonidal pits in the perineum anterior to the anus without abscess.

An otherwise healthy 20-year-old man with a history of pilonidal disease presented to clinic for evaluation of pain near the sacrum and gluteal cleft. He twice underwent incision and drainage of a gluteal cleft abscess and was seen most recently by the pediatric surgery department 2 years ago. The patient remained asymptomatic until his current presentation. On physical examination, he was found to have another pilonidal abscess with numerous associated pits and sinus tract, leading to incision and drainage at bedside with chemical cauterization of granulation tissue. Due to concern for recurrent and chronic disease, it was recommended that he not undergo formal excision until after resolution of the acute infection.

Several days later, the patient was taken to the operating room for a Bascom cleft lift procedure with tissue transfer and a rotational advancement flap. Intraoperatively, a large abscess cavity and sinus tract were observed superior to the portion of the gluteal cleft. There were additional sinuses and smaller abscess cavities in the inferior portion, with the most caudal sinus opening 4 cm superior to the anal verge. Incidentally, there were 2 pilonidal pits in the perineum anterior to the anus with no abscess; this area was clipped, and the hairs were removed (Figure). This was not previously seen on physical examination during clinic visits. The gluteal cleft and perineum were clipped of hair with hair clippers. Tufts of hair were removed from sinus tracts in both the perineum and the gluteal cleft. There was a copious amount of seropurulent fluid expressed from the superior portion of the wound. The wounds and sinus tracts were then irrigated with a 50:50 solution of peroxide and water until clear, as hydrogen peroxide has been shown to decrease recurrence of pilonidal disease and improve healing time.⁶  

The lateral safety lines had previously been marked with the patient standing. The Bascom incision was then marked out with the flap to be excised on the patient’s left side and the flap for closure on the right side. Incision was made on the right side of the marked flap, and a 5-mm flap was raised to the lateral safety line on the right side. The pilonidal disease was then excised from the medial portion of that incision to the left lateral safety line where the Bascom incision had been marked, and the paddle of pilonidal disease was excised. The total wound length was 25 cm and the width was 5 cm, leaving a defect of 125 cm². The abscess cavities and sinus tracts were then opened with electrocautery, and all granulation tissue curetted. Dense scar tissue in the base of the wound was incised with the electrocautery and left in-situ for closure. A 15-French Blake drain was placed in the depth of the wound, exiting the right buttock superiorly, and another 15-French Blake drain was placed in the more superficial part of the wound, exiting the left buttock superiorly. The right-sided flap was then rotated around the anus and advanced to the left by closing in multiple layers using 2-0 and 3-0 polyglactin sutures, including a deep dermal stitch, covering the entire defect. The skin incision was then closed with a running 3-0 polyglycolic acid barbed suture and wound adhesive.

At this time, the decision was made to leave the pilonidal pits of the anterior perineum because the rotational flap of the Bascom cleft flap was unable to be utilized given the location of the pits relative to the flap. Consequently, the anterior perineal disease was treated only with removal of hair from within the pits and clipping the hair of the perineum. Postoperatively, the patient’s wound healed appropriately, and he returned to work without any issues.

In a typical presentation of pilonidal disease of the sacrococcygeal region, treatment ranges from control of active infection via incision and drainage, excisional procedures with or without reconstruction, or nonoperative treatment involving routine hair clipping and pit picking.  Injecting phenol is no longer recommended.⁵ Various surgical techniques have been described for treatment of the more common presentation of pilonidal disease, including the Bascom cleft procedure, the Limberg flap, and the Karydakis flap, all of which aim to close the remaining defect off midline to prevent tension on the repair.^1,2 The authors’ practice frequently employs the Bascom cleft procedure for typical presentations of pilonidal disease, which has shown high success rates in other practices as well.⁷ The procedure involves excising the midline pits while a lateral incision undermines the midline and allows for active curettage of the underlying sinus tracts, leaving healthy subcutaneous tissue behind. The opposite side of the gluteal cleft is mobilized across the natal cleft, leaving the new defect off of midline and thus reducing tension on the repair.

However, pilonidal disease of the anterior perineum is rare and often not described in the literature as most cases occur in the gluteal cleft and presacral region. Several reports have identified rare presentations of pilonidal disease, some involving the umbilicus and other areas of the body.^8,9 Additionally, occupationally acquired pilonidal sinus tract of the web spaces between the fingers has been described and successfully cured with excision and primary closure.¹⁰ Furthermore, 4 case reports have identified pilonidal disease of the anterior perineum, which were all initially misdiagnosed as an anal fistula, thus highlighting the significance of this case report. Eberspacher et al¹¹ reported successful treatment of pilonidal disease of the anterior perineum by performing a “fistulectomy” on the initially perceived fistula. After finding hair in the sinus and confirming the misdiagnosis as pilonidal disease, the surgical team proceeded with primary reconstruction of the fistulectomy with successful results.¹¹ This only represents one such case with successful treatment. Thus, to determine the ideal treatment options for a rare case of pilonidal disease involving the anterior perineum, further reporting of such presentations needs to be encouraged.

It is important to note that this is an example of pilonidal disease of the anterior perineum that went untreated surgically. To identify ideal treatment options, further cases will need to be reported where surgical treatment is carried out and the long-term outcomes are analyzed. Additionally, while the patient in this study healed appropriately, final images of the Bascom cleft lift procedure were not taken.

Literature describing pilonidal disease in the anterior perineum is rare. Surgical options for gluteal cleft disease have been described, but the ideal treatment options for involvement of the anterior perineum remains unclear. As such, further studies need to be reported describing pilonidal disease of the anterior perineum with successful treatment.