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Pilonidal Sinus

Essentials

  • A common cause of recurrent abscesses in the natal cleft.
  • The condition is acquired, and it is possible to reduce its risk factors.
  • In an acute phase, the abscess is incised and drained.
  • Surgical intervention is often needed in chronic cases.

Definition, risk factors and symptoms

  • Pilonidal sinus is an acquired condition affecting the natal cleft area (the cleavage between the buttocks) where hairs have become trapped in the subcutaneous tissue and form a cavity.
  • The subcutaneous cavity easily becomes infected and a painful abscess may develop.
  • Risk factors include obesity, deep natal cleft and hairiness, an occupation requiring prolonged sitting and pilonidal sinus in the immediate family. Patients with hidradenitis suppurativa Hidradenitis Suppurativa are at increased risk of pilonidal sinus.
  • Pilonidal sinus is most common in men aged between 15 and 30 years.

Diagnosis

  • Often a clinical diagnosis is sufficient.
  • If necessary, a probe can be used to assess the size of the cyst and the extent (pilonidal sinus is usually towards the cranial direction in the midline).
  • In a quiescent phase, a non-tender nodule may be palpated in the cranial parts of the natal cleft. Midline pores (pits) may be seen in the skin.
  • In an acute situation, the nodule is painful, reddened and pus may be secreted.
  • Imaging studies are usually not helpful.

Differential diagnoses

Treatment Fibrin Glue for Pilonidal Sinus Disease

  • In an acute phase, the abscess is incised under local anaesthesia laterally to the natal cleft (for example, a scalpel blade no. 11). The skin overlying the cavity is infiltrated with local anaesthetic.
  • The debridement of inflamed granulation tissue, necrotic tissue and any hair present is carried out using an appropriate instrument and the cavity is then rinsed with, for example, normal saline. The incision wound is left openHealing by Primary Versus Secondary Intention after Surgical Treatment for Pilonidal Sinus, and the tissue growth closing the wound starts at the bottom of the cavity.
  • A ribbon gauze dressing (e.g. Sorbact® ) may be left in the cavity to absorb the bacterial mass. The wound is showered or irrigated morning and evening for a few days.
  • Systemic antimicrobials are generally only indicated if cellulitis of the surrounding tissue is suspected Erysipelas or the patient has risk factors.
  • The antimicrobials and treatment period are the same as used in the management of an abscess Skin Abscess and Folliculitis: for example, flucloxacillin 750-1000 mg three times daily or cephalexin 500-750 mg three times daily for 7-10 days.
  • In cases of hypersensitivity, clindamycin may be used.
  • The treatment of pilonidal sinus should not consist repeatedly solely of systemic antimicrobials.
  • After the procedure, it is important to pay attention to meticulous hygiene in order to keep hair and other contaminants from entering the wound.

Prevention of recurrence

  • Abscess recurrence is common.
  • The best preventative methods against recurrence are good local hygiene, reduction of time spent sitting down and weight loss.
  • Any pressure exerted on the natal cleft should be minimised by employing ergonomic planning procedures at the workplace.
  • Hair and debris should be removed when washing.
  • Hair removal (shaving, chemical or laser depilation) has been shown to prevent recurrences.

Specialist consultation

  • A surgical opinion should be sought in complicated and recurring cases; several surgical techniques are in use. Less invasive methods are also used.
  • Surgical removal of asymptomatic sinuses is usually not worthwhile.

    References

    • Bi S, Sun K, Chen S, et al. Surgical procedures in the pilonidal sinus disease: a systematic review and network meta-analysis. Sci Rep 2020;10(1):13720 [PubMed]
    • Grabowski J, Oyetunji TA, Goldin AB, et al. The management of pilonidal disease: A systematic review. J Pediatr Surg 2019;54(11):2210-2221 [PubMed]
    • Kalaiselvan R, Bathla S, Allen W, et al. Minimally invasive techniques in the management of pilonidal disease. Int J Colorectal Dis 2019;34(4):561-568 [PubMed]
    • Benhadou F, Van der Zee HH, Pascual JC, et al. Pilonidal sinus disease: an intergluteal localization of hidradenitis suppurativa/acne inversa: a cross-sectional study among 2465 patients. Br J Dermatol 2019;181(6):1198-1206 [PubMed]
    • Halleran DR, Onwuka AJ, Lawrence AE, et al. Laser Hair Depilation in the Treatment of Pilonidal Disease: A Systematic Review. Surg Infect (Larchmt) 2018;19(6):566-572. [PubMed]
    • Milone M, Velotti N, Manigrasso M, et al. Long-term follow-up for pilonidal sinus surgery: A review of literature with metanalysis. Surgeon 2018;16(5):315-320. [PubMed]
    • Guner A, Cekic AB, Boz A, et al. A proposed staging system for chronic symptomatic pilonidal sinus disease and results in patients treated with stage-based approach. BMC Surg 2016(16):18. [PubMed]