Pilonidal Disease

Updated: Jul 01, 2021
Author: M Chance Spalding, DO, PhD; Chief Editor: John Geibel, MD, MSc, DSc, AGAF 



Pilonidal disease was first reported in 1833. This process was first described by Anderson in 1847 and later named pilonidal sinus by Hodges in 1880.[1] The word pilonidal derives from the Latin words pilus ("hair") and nidus (“nest”).

Sacrococcygeal pilonidal sinus is a common disorder among young adults. Observed most commonly in people aged 15-30 years, with a 3:1 male-to-female ratio, it occurs after puberty, when sex hormones are known to affect the pilosebaceous gland and change healthy body hair growth. The onset of pilonidal disease is rare in people older than 40 years.[2]

In the 1950s, pilonidal sinus disease was thought to be of congenital origin rather than an acquired disorder. The pilonidal sinus and abscess were thought to be secondary to a congenital remnant of an epithelial-lined tract from postcoccygeal epidermal cell rests or vestigial scent cells. Sinuses to the neural canal can occasionally extend to the dura, but these are rare and are located in the lumbar region rather than in the sacral region.

Pilonidal disease is now widely considered to be an acquired disorder, on the basis of observations that congenital tracts do not contain hair and are lined with cuboidal epithelium. The pilonidal cyst is also not a true cyst, in that it has an epithelialized walls and is more of a cavity, which makes a congenital origin less likely. The recurrence of the disorder after complete excision of the disease tissue down to the sacrococcygeal fascia and the high incidence of chronic pilonidal sinus disease in patients who are hirsute further support an acquired theory of pathogenesis.

In a census and survey of patients admitted to British hospitals in 1985 for treatment of pilonidal sinus disease, it was found that 7000 patients required hospitalization for an average of 5 days. The hospitalization of these patients for the treatment of pilonidal disease resulted in a loss of productivity and earnings, as well as a disruption of education, because patients recovered in the hospital. In the 1980s, Bascom found that at least 40,000 US soldiers were admitted to the hospital for an average of more than 5 days of inpatient care for pilonidal disease and associated complications.

Treatment options are now available that provide a rapid rate of cure and a lower recurrence rate and minimize the number of hospital admissions. Although numerous randomized clinical studies have evaluated different treatments, no clear consensus has been reached as to the optimal medical or surgical treatment of pilonidal disease.

For patient education resources, see the Skin Conditions and Beauty Center, as well as Pilonidal Cyst and Skin Abscess.


A pilonidal sinus can occur in many different areas of the body, but most are found in the sacrococcygeal area, in the natal cleft, approximately 5 cm from the anus. The characteristic pilonidal sinus is a midline opening in the sacrococcygeal area in the natal cleft. Not uncommonly, the patient may have a series of openings in the midline or may have secondary lateral openings superior to the midline pit.

The sinus tract itself is smooth and lined with squamous epithelium. Eventually, the sinus tract leads to a subcutaneous cavity lined with granulation tissue and filled with nests of hair. The sinus tract openings are actually an extension of the deep cavity. This is why an abscess formation may present either in the midline or lateral to the midline.


After the onset of puberty, sex hormones affect the pilosebaceous glands, and subsequently, the hair follicle becomes distended with keratin. In pilonidal disease, a folliculitis develops, which produces edema and follicle occlusion. The infected follicle extends and ruptures into the subcutaneous tissue, forming a pilonidal abscess. This results in a sinus tract that leads to a deep, subcutaneous cavity.

In 90% of cases, the direction of the sinus tract is cephalad, which coincides with the directional growth of the hair follicle. This usually places the tracking follicle approximately 5-8 cm from the anus. In the rarer instance that the sinus is located caudally, it is usually found 4-5 cm from the anus. The caudal location of the sinus can be easily mistaken for a fistula-in-ano and should be considered before treatment.[3]

The laterally communicating sinus overlying the sacrum is created as the pilonidal abscess spontaneously drains to the skin surface. The original sinus tract from the natal (intergluteal) cleft becomes an epithelialized tube. The laterally draining tract becomes a granulating sinus tract opening.

Loose hairs are drilled, propelled, and sucked into the pilonidal sinus by friction and the movement of the buttocks whenever a patient stands or sits. This bending and sitting action tightens the skin of the gluteal cleft and lifts it from the fascia. The negative pressure drives hair deeper into the sinus and appears to be exaggerated with a deep gluteal cleft.[4]

Hair enters tip first, and the barbs on the hair prevent it from being expelled, causing the hair to become entrapped. Physical examination occasionally may reveal a tuft of hair emerging from the midline opening in the natal cleft. This trapped hair stimulates a foreign body reaction and infection. Rarely, foreign bodies other than human hair can cause this disease process. Rare case reports exist in which the hair did not come from the patient but instead came from a bird's feather, the type used to stuff feather bedding.


The etiology of pilonidal disease has been surrounded by controversy. In the 1950s, as noted (see above), the predominant thinking was that this was a congenital condition; however, current theories focus primarily on predisposing factors and acquired conditions.[4]

The incidence of pilonidal disease is also affected by hair characteristics, such as kinking, medullation, coarseness, and growth rate. White persons are affected more frequently than are African or Asian persons. Other factors affecting the disease's incidence are increased sweating activity associated with sitting[5] and buttock friction, poor personal hygiene, obesity, and local trauma, which help to explain why pilonidal sinus disease is common in army recruits.

Predisposing factors to pilonidal disease are believed to include the following[6] :

  • Obesity
  • Sedentary lifestyle or occupation
  • Deep natal cleft
  • Family history of pilonidal disease

In an article examining the condition in Turkish soldiers, the incidence was found to be 8.8%, with the correlation factors known to be family history, obesity, being the driver of a vehicle, and the presence of folliculitis or a furuncle at another site on the body.[7]


The incidence rate of pilonidal disease is approximately 0.7%. Males are affected 2.2-4 times more frequently than females. During a population study involving college students, the incidence rate was found to be 1.1% (365 of 31,497 people) in males and 0.11% (24 of 21,367 people) in females. The onset of the disease is earlier in females, which may be due to the fact that puberty occurs earlier in females.


Irrespective of the method of treatment applied, very few patients are troubled with symptoms of persistent pilonidal disease beyond the age of 40 years. This is important to note because ultimately, cure is an almost inevitable result that comes with age, regardless of the choice of surgical management.

Few prospective, randomized, controlled trials have compared one treatment of pilonidal disease with another. However, one such study compared primary closure with excision in 110 patients and found that the former was associated with longer hospitalization, though it was also associated with earlier return to work.[8]  In addition, the primary closure group had an increased risk of infection and a higher recurrence rate. Nevertheless, the authors suggested that both procedures have a place in treatment and that the choice depends on surgeon preference.

It appears that no definitive comparisons of outcomes are available as yet; however, some suggest that open drainage procedures have a lower risk of infection.



History and Physical Examination

Although pilonidal disease may manifest as an abscess, a pilonidal sinus, a recurrent or chronic pilonidal sinus, or a perianal pilonidal sinus, the most common manifestation of pilonidal disease is a painful, fluctuant mass in the sacrococcygeal region.

Initially, 50% of patients first present with a pilonidal abscess that is cephalad to the hair follicle and sinus infection. Pain and purulent discharge from the sinus tract are present 70-80% of the time and are the two most frequently described symptoms. In the early stages preceding the development of an abscess, only a cellulitis or folliculitis is present. The abscess is formed when a folliculitis expands into the subcutaneous tissue or when a preexisting foreign body granuloma becomes infected.

The diagnosis of a pilonidal sinus can be made by identifying the epithelialized follicle opening, which can be palpated as an area of deep induration beneath the skin in the sacral region. These tracts most commonly run in the cephalad direction. When the tract runs in the caudal direction, perianal sepsis may be present.

The distinctions among pilonidal disease, fistula-in-ano, and hidradenitis can be difficult to discern. In the differential diagnosis, also include skin furuncle, syphilitic granuloma, tubercular granuloma, and osteomyelitis of the underlying sacrum with a draining sinus.

Recurrent pilonidal disease is most often observed after incision and drainage of a pilonidal abscess. In this setting, the pilonidal sinus has not been excised and remains after the abscess cavity heals, only to precipitate a recurrence. After surgical excision, the hair follicle has been removed and is no longer the precipitating cause of the chronic pilonidal sinus. Instead, the base of the unhealed surgical wound is believed to become filled with granulation tissue, hair, and skin debris, which is a nidus for the ongoing foreign body reaction that causes the chronic disease.

Endoanal pilonidal sinus is a rare variety of pilonidal disease that affects the perianal skin directly or may occur circumferentially around the anus, involving the skin of the anal verge.[9]  Three causes of perianal pilonidal disease have been described, as follows:

  • First, the pilonidal sinus may tract down caudally, creating a perianal fissure or fistula communicating with the anal canal
  • Second, hair may enter the healing wound of a surgically managed fistula-in-ano
  • Third, hair may be propelled, penetrating the normal anoderm and producing a similar foreign body reaction, which is usually observed in the sacrococcygeal region


Approach Considerations

Pilonidal disease is diagnosed on the basis of the history and physical examination. The typical location of the midline pits superior to the anus and overlying the sacrum and coccyx is a hallmark of the disease.[10] Occasionally, pilonidal disease can track from a fistula around the anal canal and consequently be confused with anal fistula; however, this is rare. During physical examination, broken hairs can often be extracted from the pilonidal sinus.

Laboratory Studies

Routine laboratory data are not necessary in the treatment of pilonidal disease. Studies should be ordered if warranted by the patient’s medical history and if required for preoperative testing.

Imaging Studies

Imaging studies are not routinely obtained for pinodal disease; however, there have been reports of complicated disease progressing to osteomyelitis, necrotizing fasciitis, toxic shock syndrome, and meningitis.[11]

Histologic Findings

After the onset of puberty, sex hormones affect the pilosebaceous glands, and subsequently, the hair follicle becomes distended with keratin. As a result, a folliculitis develops that produces edema and follicle occlusion.

The infection tracks away from the surface in the trajectory of the occluded follicle. This usually places the tracking follicle approximately 5-8 cm from the anus. In the rarer instance that the sinus is located caudally, it is usually found 4-5 cm from the anus. The laterally communicating sinus overlying the sacrum is created as the pilonidal abscess spontaneously drains to the skin surface. The original sinus tract from the natal cleft becomes an epithelialized tube. The laterally draining tract becomes a granulating sinus tract opening.



Approach Considerations

The ideal treatment for a pilonidal sinus varies according to the clinical presentation of the disease. First, it is important to divide pilonidal disease into the following three categories, which represent different stages of the clinical course:

  • Acute pilonidal abscess
  • Chronic pilonidal disease
  • Complex or recurrent pilonidal disease

Surgical management is then tailored to the classification category. Although there are several treatment options for pilonidal disease in each category, they all have similar goals, as follows:

  • Wound healing with a low risk of recurrence
  • Short hospitalization
  • Maximal patient comfort
  • Low morbidity, with few wound-management problems

In addition, treatment should allow the patient to resume normal daily activities as quickly as possible.

Ideally, the method used to treat the patient should satisfy all of these goals. A definite shift has occurred among physicians toward treating these patients in an outpatient setting. Current proponents of nonoperative management point out that regardless of the therapy used, the pilonidal disease resolves after the age of 40 years. These physicians focus their efforts on conservative medical management of pilonidal disease rather than on a surgical cure for the disorder.

Concern surrounding long-term pilonidal disease is secondary to the rare occurrence of squamous cell carcinoma found in the pilonidal sinus tracts. The treatment is similar to that of other squamous cell carcinomas (ie, excision and grafting if necessary). There has been discussion about the utility of treating this disease process with chemotherapy and radiation after excision, an approach that is increasingly common with high-risk disease.[12]

No specific contraindications exist for the treatment of pilonidal disease. Acute infections should be drained; however, when more extensive procedures are required, every effort should be made to perform these in a noninfected field.

Practice parameters for the management of this disease have been developed by the American Society of Colon and Rectal Surgeons (ASCRS). (See Guidelines.)

Medical Therapy

There are several medical treatments for pilonidal sinuses. It is fairly widely agreed that an abscess formed from a pilonidal sinus should undergo surgical treatment with incision and drainage. However, regimens for elective treatment of pilonidal sinuses vary widely.

One of the simplest medical treatments of pilonidal sinuses is to shave the sacral area free of hair and to pluck all visible embedded hair in the sinus. There have been several suggestions of applying laser hair removal treatments to this region to decrease the likelihood of further exacerbations. To date, however, no clinical trials have documented success with this therapy as compared with more traditional treatments.[13]

Lord and Millar popularized their technique of coring out the midline epithelial follicles, but they also included a brush in their procedure to cleanse the cored cavity of hair and any hair left over in the remaining laterally oriented, granulation-lined tract. The brushing of the tracts continues in the outpatient setting until the tract heals completely and closes. The follicle excision sites may be closed primarily but are usually packed and dressed to heal by secondary intention.

In Europe it is much more common to treat pilonidal sinuses with phenol injections[14, 15, 16] than it is in the United States. Both chronic pilonidal disease and acute pilonidal abscess (after incision and drainage) may be managed by phenol injection.

In this procedure, 80% phenol is injected into the sinus, left there for 1 minute, and then expressed out of the cavity. The sinus is then curetted. This can be repeated as many as three times, for a total of 3 minutes of phenol exposure during a single treatment. The treatments may be repeated every 4-6 weeks as necessary, as wound healing progresses. Paraffin jelly may be used to protect the skin from the phenol, which destroys the epithelium.

Phenol sterilizes the sinus tract and removes embedded hair. Phenol injections may be combined with local excision of the sinus. Wound healing usually requires 4-8 weeks. The incidence of recurrence is reported to be in the range of 9-27%, which is similar to the incidence following simple excision and packing open the wound.

Because of the intense local inflammatory response after the phenol injection, patients usually stay in the hospital overnight. Thereafter, the patient is allowed to return home, with instructions to bathe daily and follow a postoperative hair removal regimen, including shaving of the surrounding areas on a near-daily basis. Dressings are used for comfort.

A newer medical therapy that is applied after simple curetting of the sinus tract is fibrin glue. The glue is applied to each individual tract after curettage, and the excess is then wiped away.[17] Early data showed a reduction in time to return to work. Reports suggested that healing rates were comparable to those of the Bascom operation (see Surgical Therapy).[10]  An early-2017 Cochrane review found, however, that the currently available evidence was insufficient to determine whether fibrin glue offered a significant benefit in this setting, either alone or in conjunction with surgery.[18]

Radiofrequency ablation (RFA) techniques have also been studied in an attempt to reduce the pain associated with the procedures.[19]  Laser ablation of the pilonidal sinus is receiving interest as well.[20]

These innovations reflect the ongoing effort to define an approach to the treatment of pilonidal disease that is less invasive than standard methods but at least equally effective.

Surgical Therapy

Acute pilonidal abscess

A pilonidal abscess is managed by incision, drainage, and curettage of the abscess cavity to remove hair nests and skin debris. This can be accomplished in the surgical office or in the emergency department, using local anesthesia.[21]

If possible, the drainage incision should be made laterally, away from the midline. Wounds heal poorly in the deep, intergluteal natal cleft, for two reasons. The first is the frictional motion of the deep cleft, which creates continuous irritation to the healing wound; the second is the midline nature of the wound, which is a product of constant lateral traction during sitting.

The wound should be cleansed daily in the shower or with a sitz bath. Paying close attention to hygiene and hair shaving of the surrounding area is important in preventing hair from penetrating the healing scar and causing further pilonidal sinuses to form.

This meticulous treatment of the diseased area should continue for approximately 3 months, even after the wound has completely healed. In more than 90% of cases, the wound heals completely in approximately 1 month. In approximately 60% of patients, incision and drainage without curettage results in wound healing within 10 weeks. Of these patients, 40% develop a recurrent pilonidal sinus that requires further treatment.

When incision and drainage of an abscess is performed for pilonidal disease, the patient should be informed that this is not a curative procedure. Some studies have shown that as many as 85% of patients require further surgical treatment.

Excising the pilonidal pit at the time of abscess drainage reduces the recurrence rate to 15%. The difficulty with doing this is that the pilonidal pit initially cannot be identified during the first drainage procedure of the abscess, because of the acute inflammatory response surrounding the abscess. Approximately 5 days later, when the edema is reduced, the pit can be identified.

Chronic pilonidal disease

Chronic pilonidal disease is the term applied when patients have undergone at least one pilonidal abscess drainage procedure and continue to have a pilonidal sinus tract. The term also refers to a pilonidal sinus that is associated with a chronic discharge without an acute abscess. Surgical options for management of a noncomplicated chronic pilonidal sinus include the following:

  • Excision and laying open of the sinus tract
  • Excision with primary closure
  • Wide and deep excision to the sacrum
  • Incision and marsupialization
  • Bascom procedure
  • Asymmetrical incisions

Excision and laying open of sinus tract

An option has been described in which the pilonidal sinus is excised and the tract is laid open to allow healing by secondary intention; this technique, which is intended to ensure adequate drainage for the cavity,[22] avoids the wound infections that can be seen after primary closure. This technique can be either the primary treatment option or a secondary option chosen with a view to wound tension. In cases where the primary closure is not free of tension, the wound can be left to heal by laying the tract open.

Even after the pilonidal sinus has been excised down to healthy presacral fascia, the wound is still considered contaminated. Aerobic and anaerobic organisms are found in 50-70% of wounds.

The disadvantages of laying the tract open are the inconvenience to the patient, with frequent dressing changes, and the need for close observation of the wound to ensure proper wound healing and to avoid premature closure of the skin edges. The average time for wound healing to occur is approximately 6 weeks. Laying the tract open is always appropriate when a cellulitis is surrounding the pilonidal sinus. Not uncommonly, wounds may require 4-6 months to heal, but the average healing time is approximately 2 months.

The recurrence rate is in the range of 8-21%. The reduced recurrence rate is believed to be due to the more broad-based, flattened, and hairless scar produced by secondary intention.[23] This prevents buttocks friction, hair penetration, and hair follicle infection. Although advantages exist, the disadvantages associated with these open wounds (ie, aggressive management in the form of frequent dressing changes and close observation by the patient and surgeon) must be taken into account.

Because of the poor quality of life that results from open excision and packing in the surgical treatment of pilonidal disease, Spyridakis et al evaluated whether platelet-derived growth factors (PDGFs) could speed the wound-healing process.[24] Results from a controlled trial involving 52 patients indicated that postoperative treatment with local infusion of growth factors hastens recovery.

In this study,[24] patients who received the PDGFs went back to their normal activities approximately 17 days after surgery, when mean wound volume was about 10 cm3, whereas control group patients returned to normal activities around postoperative day 25. Surgical wounds in the platelet group healed completely in 24 days; wounds in the control group took more than 30 days to heal. The authors concluded that PDGFs enhance the healing process, thereby shortening patient recovery time.

Excision with primary closure

Excision of a pilonidal sinus[21] entails excision of the midline pits and lateral openings down to the presacral fascia, with removal of minimal surrounding skin. In general, it is unnecessary to remove more than 0.5 cm of skin surrounding the sinus opening. Curetting the wound to remove hair, granulation tissue, and skin debris is essential for promoting adequate wound healing. Although this procedure can be performed with local anesthesia alone, the addition of mild sedation to local anesthesia allows a more complete excision and a more comfortable patient.

Primary wound closure and wound healing by secondary intention are the two principal surgical options for a chronic pilonidal sinus.[22, 6] There remain some differences between these two approaches with regard to wound healing and recurrence. Although primary closure has the potential for earlier wound healing if infection does not occur, it does require that the patient restrict many activities until wound healing is complete.

The incidence of failed primary healing is approximately 16%. This is because a primary closure is rarely completely free of tension and because the wound is considered contaminated despite excision and debridement. Recurrence rates after primary closure may be as high as 38%. Although the technique of excising the pilonidal disease and allowing the patient to heal by secondary intention requires a longer healing time, it is associated with a lower recurrence rate.

In a study that included 242 patients with symptomatic pilonidal disease, Khodakaram et al compared conventional wide excision (n=129) with a modified Lord-Millar (mLM) approach consisting of minimal excision of pilonidal sinuses with primary suture (n=113).[25] The mLM operation was associated with more frequent use of local anesthesia, a lower frequency of hospital admission, fewer postoperative health care visits (2.4 vs 14.6), and a shorter average sick leave (1.0 vs 34.7 days). Estimated 5-year recurrence rates were similar (32 vs 23%). Cost per operated patient and utilization of hospital resources were also lower for the mLM group.

Incision and marsupialization

Marsupialization as a treatment option of a pilonidal sinus was first introduced in 1937. It represents a compromise between primary wound closure and wound healing by secondary intention. The aim is to avoid wound infection and dehiscence after primary closure, as well as frequent packing of the open wound.

With marsupialization, the wound is sutured open. After excision of the pilonidal sinus, cavity, and lateral tracts, the cavity is scrubbed and curetted to remove hair and granulation tissue. The skin edges of the wound are then sutured to the presacral fascia. Finally, the wound is loosely packed; daily dressing changes are required.[6, 26]

Marsupialization provides the patient with a smaller wound as compared with wounds that are left open to granulate. By suturing the wound open, wound infection is prevented and the subcutaneous tissue is covered, resulting in reduced healing time. Healing is usually complete by 6 weeks, and the recurrence rate has been reported to be 4-8%.

Many authors consider marsupialization to be the preferred method of treatment for chronic pilonidal disease because it avoids closure of a contaminated wound and combines shorter healing times with a lower recurrence rate. The patient still needs to pay meticulous attention to personal hygiene, with daily wound cleansing and frequent hair shaving and removal.

Bascom procedure

Bascom and Edwards described a procedure in which pilonidal disease was treated with only removal of the hair and the follicles.[27, 28] The recurrence rate in these early reports was 8%, and all of the patients healed within 3 weeks of the procedure. Since the initial reports, there have been several studies that showed comparable results.[29, 30]

The Bascom procedure focuses on avoiding the midline incision and performing a minimal amount of tissue removal. The approach is described as consisting of a lateral incision, removal of the hair, and excision of the sinus tract with small incisions overlying each sinus. The lateral incision is tunneled medially toward the base of the sinus tract, and this region can be curetted to remove the base of the sinus.

The cavity is cleansed and either closed primarily or packed open, depending on the operator's preference. The advantages of a primary closure are small wounds, a shorter healing time (usually ≤3 weeks), minimal wound care, earlier return to work, and no need for daily scheduled dressing changes. The obvious disadvantages are wound infection and wound dehiscence.

Asymmetrical incisions

Rather than primarily closing a midline or lateral vertical incision, some physicians advocate the use of asymmetrical[23] or oblique elliptical incisions in an attempt to keep incisions out of the natal cleft. In this way, the procedure can be performed in a midline vertical orientation, with the final incision being lateral to the gluteal cleft.

This operation, often termed the Karydakis procedure,[31, 32] begins with excision of the wound and en-bloc removal of the sinuses with an elliptical specimen of overlying skin. The incision is made off the midline. Once the wound is excised, a full-thickness flap is created on the opposite side from the semilateral incision; this allows the opposite side to be mobilized for primary wound closure, thus avoiding a midline wound. The wound is closed in multiple layers over a closed suction drain.

This technique has been used as a primary procedure for surgical management or for complicated disease. The disadvantage is that the dissection is too extensive for an outpatient setting. The recurrence rate is reported to be 1.3%. Although the use of an incision that crosses the vertical gluteal fold to excise the pilonidal cavity does eliminate a vertical suture line within the gluteal fold,[33] healing times may remain considerable.

Skin flaps have also been described to cover a sacral defect after wide excision. Similarly, this keeps the scar off the midline and flattens the natal cleft. The potential complications include loss of skin sensation in the flap, which is observed in more than 50% of patients, and necrosis of the flap edges. Again, primary healing is achieved in 90% of cases.

Complex or recurrent pilonidal disease

See Complications for information about surgical therapy for complex or recurrent pilonidal disease.


Patients with recurrent pilonidal disease or complex, unhealed pilonidal wounds present a challenge to the surgeon. Tissue loss from previous attempts at excision further complicates the surgical management and limits options. The causes of recurrence are thought to include the following:

  • Unrecognized sinus at the time of the initial excision
  • Repeated infections of the scar, causing abscess
  • Intergluteal cleft anatomy that promotes the accumulation of perspiration, friction, and the tendency for hair to grow into the scar

The midline scar is the most susceptible to the recurrence of pilonidal disease and poor wound healing.

The techniques developed for recurrent disease and unhealed wounds generally involve the use of a flap procedure to achieve primary closure and to obliterate the deep natal cleft. This relocates hair follicles away from the midline and prevents the frictional forces associated with the principal etiologic factors in the development of pilonidal disease. Flap closure should be reserved for complex or recurrent pilonidal disease that has failed to respond to the simple, conservative operative techniques that are initially used to treat chronic pilonidal disease.

A wound that has not responded to initial therapy must be reexcised down to the sacrococcygeal fascia. The reexcision must include the unhealed wound, scar, and granulation tissue. A flap procedure[34, 35, 36, 37, 38] is then performed to achieve primary wound closure. The techniques available include the following:

  • Cleft closure
  • Advancement flap (Karydakis procedure [31, 32] )
  • Local advancement flap (3-plasty rhomboid flap [34] or V-Y advancement flap)
  • Rotational flap (gluteus maximus myocutaneous flap)

The cleft closure technique involves excising the wound with a triangular incision, with the apex of the incision lateral to the apex of the natal cleft. The inferior margin becomes crescent-shaped, with its point positioned towards the anus. A skin flap involving only the dermis is created on the convex side of the lower wound margin.

Before the procedure is begun, the line of contact of the buttocks is marked to define the lateral edge of the raised skin flap. The two skin edges are then overlapped, and the excess skin is excised. This creates a primary closure that is off the midline and obliterates the intergluteal cleft. The wound is closed in multiple layers over a closed suction drain. The recurrence rate is reported to be 3.3%.

The advancement flap or Karydakis procedure[31, 32] (described earlier) can be used as a primary procedure or for the treatment of recurrent complicated disease.

Local advancement flaps (eg, the 3-plasty rhomboid flap and the V-Y advancement flap) are used to cover defects resulting from recurrent pilonidal disease. However, such flaps in the pilonidal area may be at risk for compromised vascularity as a consequence of continued infection, external compression, cigarette smoking, and tension on the flap. Accordingly, whenever an advancement flap is contemplated, a myocutaneous flap should be considered.

Complex wounds are reconstructed by using muscle and myocutaneous flaps because these flaps typically heal well and cover areas of extensive skin loss. Compared with skin flaps, they are less susceptible to infection and have a predictable vascular supply that promotes safe elevation and better wound healing.

Reconstructions using muscle and myocutaneous flaps are technically demanding, usually requiring the assistance of a plastic surgeon; however, they produce reliable results (with recurrence rates of 6-20%). Among the disadvantages of such procedures is that they necessitate prolonged hospitalization, require longer operating times, and are associated with more serious complications.

A failed flap represents a significant morbidity that ultimately leads to more extensive skin loss and a wound that is difficult to manage. These procedures are reserved for surgical management of complex recurrent wounds when more conservative procedures have failed.

Long-Term Monitoring

With excision of pilonidal disease and healing by secondary intention, the open wounds left after surgery require aggressive management in the form of frequent dressing changes, cleansing, hair removal, and close observation by the patient and surgeon.



Guidelines Summary

In 2019, the American Society of Colon and Rectal Surgeons (ASCRS) published the following practice parameters for the management of pilonidal disease[39] :

  • Perform a disease-specific history and physical examination, with particular attention paid to risk factors, symptoms, and presence of secondary infection
  • As a primary or adjunctive treatment, shaving or laser epilation may be used to eliminate hair from the gluteal cleft and surrounding skin in either acute or chronic pilonidal disease, unless an abscess is present
  • An effective treatment that can achieve rapid and durable healing in patients with acute or chronic pilonidal disease without abscess is phenol application
  • Fibrin glue can be efficacious as a primary or adjunctive treatment in patients with chronic pilonidal disease without abscess
  • It remains unclear if prophylactic intravenous and/or topical antibiotic treatment is of value in pilonidal disease surgery; individualized case-by-case consideration is recommended
  • In patients with acute pilonidal disease with an abscess, treat with incision and drainage in both primary episodes and recurrent episodes.
  • Based on surgeon and patient preference, recommended treatment options in patients who require surgery for chronic pilonidal disease include (1) excision and primary repair, with consideration for off-midline closure; (2) excision with healing by secondary intention; and (3) excision with marsupialization; drain use should be individualized on a case-by-case basis
  • Flap-based procedures remain an option, particularly in cases of complex and recurrent chronic pilonidal disease when other techniques have failed
  • Minimally invasive approaches, such as endoscopic techniques or video assistance, can be used in acute and chronic pilonidal disease; these require specialized equipment and expertise
  • When considering operative strategies for recurrent pilonidal disease, differentiate between the presence of an acute abscess and chronic disease, taking into consideration the expertise and experience of the surgeon

Questions & Answers


What is pilonidal disease?

What is the anatomy of the pilonidal sinus relative to pilonidal disease?

What is the pathophysiology of pilonidal disease?

What causes pilonidal disease?

Which factors increase the risk for pilonidal disease?

What is the prevalence of pilonidal disease?

What is the prognosis of pilonidal disease?


What are the signs and symptoms of pilonidal disease?

Which clinical findings are diagnostic of pilonidal disease?

How is pilonidal disease differentiated from fistula-in-ano, and hidradenitis?

What causes recurrent pilonidal disease?

What causes perianal pilonidal disease?


How is pilonidal disease diagnosed?

What is the role of lab testing in the workup of pilonidal disease?

What is the role of imaging studies in the workup of pilonidal disease?

Which histologic findings are characteristic of pilonidal disease?


What is the clinical course of pilonidal disease?

What are goals of surgical management for pilonidal disease?

How is squamous cell carcinoma treated in patients with pilonidal disease?

What are the contraindications for the treatment of pilonidal disease?

What are the nonsurgical treatments for pilonidal disease?

What is the role of phenol injections in the treatment of pilonidal disease?

What is the role of fibrin glue in the treatment of pilonidal disease?

What is the role of radiofrequency ablation (RFA) in the treatment of pilonidal disease?

Which surgical interventions are used in the treatment of chronic pilonidal disease?

What is the role of surgery in the treatment of acute pilonidal abscess?

What is the efficacy of excision and laying open of sinus tract for treatment of pilonidal disease?

What is the efficacy of excision with primary closure for treatment of pilonidal disease?

What is the efficacy of marsupialization for treatment of pilonidal disease?

What is the efficacy of the Bascom procedure for treatment of pilonidal disease?

What is the efficacy of asymmetrical incisions for treatment of pilonidal disease?

What causes recurrent pilonidal disease?

How is recurrent pilonidal disease treated?

How is complex pilonidal disease treated?

What is included in the long-term monitoring of patients with pilonidal disease?


What are the American Society of Colon and Rectal Surgeons (ASCRS) treatment guidelines for pilonidal disease?