Pilonidal sinus (PS) is a condition characterised by the ingrowth of hair in the natal cleft (between the buttocks). This leads to the formation of a sinus with hair at the apex. The sinus is unable to drain effectively and can become infected. This may lead to abscess formation, pain, and chronic drainage from the sinus (Figure 1). It affects around 26 per 100 000 population, and favours males in a 3:1 ratio.1 Those affected are typically working age. Treatment of this condition is poorly evidenced,2 and there is much variation in practice.3
Figure 1.
Pilonidal sinus abscess at base of spine. Credit: Dr P. Marazzi / SCIENCE PHOTO LIBRARY
How will pilonidal sinus present in primary care?
A small number of PS presentations will be asymptomatic. The acutely symptomatic patient typically presents with an abscess in the natal cleft, associated with pain, and difficulty sitting or walking. The chronically symptomatic patient may present with a well-established pit (sinus) or pits, and chronic drainage of pus. In some cases, there is extensive granulation tissue that might cause bleeding.
How should GPs manage mild or moderately symptomatic disease?
Acute management
Treatment should focus on drainage of sepsis and relief of pain. This can be drained by the emergency general surgery service. Antibiotics will not treat large or deep collections in this setting.
Chronic management
There are little data to support the role of antibiotics in chronic PS as a temporising measure. Patients with chronic PS should be assessed by a colorectal surgeon. This permits thorough assessment and discussion of treatment options. If the disease is only mildly symptomatic it is important that the effects of the treatment should not be worse than those of the disease. Minimally invasive interventions would be appropriate, ranging from installation of fibrin glue and pit-picking to lateral drainage and excision of the pit. Such procedures will result in minimal time off work and, typically, should be first-line treatment for this group.
When is the right time to refer?
This should be soon, after the initial presentation. The natural history of PS is poorly understood. However, it is plausible that presentations earlier in the disease process might show less complexity (for example, number of sinuses and extent of abscess). This could lend itself towards less invasive treatments. Surgeons often see patients with quite significant disease, who regret not having explored surgical treatment options sooner.4 Therefore, the right time to seek a specialist opinion is around the first symptomatic presentation. If presentation is with an abscess, then referral to the emergency surgery team is advisable. Routine outpatient referral to the colorectal team is typical. If symptoms are significant then attempts to expedite assessment can be made; however, these may be limited by system capacity.
What advice is there about cleaning the wound or about hair removal?
Surgical intervention can leave wounds that are difficult to manage because PS is located in an area that is typically warm, sweaty, and difficult to keep clean. There is also a lot of movement around that area when walking, which can delay healing. Holistic management involves addressing anything that could impede wound healing. Smoking is considered the enemy of a healthy wound, and appropriate cessation advice and support should be provided. There is a suggestion that hair removal (for example, with laser, waxing, or hair removal cream) might reduce recurrence of PS. This has not been shown in systematic reviews, but many surgeons would still advocate hair removal.3 The depth of the natal cleft is also important, as a deeper cleft is considered harder to manage. Weight loss advice may therefore be beneficial. Finally, opportunities should be taken to optimise other medical conditions that might impair wound healing, such as diabetes mellitus.
How can patients be empowered to ask good questions of surgeons?
Patients should be encouraged to think about outcomes that matter to them, specifically time off work, time for wounds to heal, and the risk of recurrence of symptoms. Surgeons have a range of techniques to treat PS. However, big operations (for example, lay open and flap procedures) are likely to cure this condition, but may mean longer time off work and delayed wound healing compared with smaller operations (for example, pit-picking and glue). Patients should be encouraged to think about what they are willing to trade for their treatment goal.
What is the best surgery available?
The treatment of PS is preference sensitive, with patients prioritising different outcomes.5 Surgeons will take into account different aspects of the patient and disease. The extent of disease is important — one pit may be more treatable with minor procedures than multiple pits, and more extensive pits, with spread off the midline, can be harder to treat. Primary disease is often easier to treat than recurrent disease. Extensive sepsis, smoking, high body mass index, and diabetic states are all factors that might make surgeons pause before an operation that leaves a big wound.
Minor treatments may not remove the pits, but can deal effectively with the symptoms, giving a significant period of symptom-free time, and an early return to normal activities and work. Major procedures will require a longer period off work. If successful, these procedures might effectively cure the disease; however, there is always a risk of a flap ‘failure’ or wound complications, prolonging recovery.
Dressings
The main aims of management with dressings are to encourage an environment that is conducive to wound healing. After the operation, some surgeons will leave a wound open. These wounds need careful management by a practice nurse, or by a formal tissue viability team. Wound care is an understudied area in PS and lacks a strong evidence base.2 There is low-certainty evidence to support the use of platelet-rich plasma, Lietofix cream, and hydrogel dressings for wound healing.6 Negative pressure dressings have also been used. There is no evidence supporting the use of topical antibiotics.
Provenance
Freely submitted; externally peer reviewed.
Competing interests
The authors have declared no competing interests.
References
- 1.Khanna A, Rombeau JL. Pilonidal disease. Clin Colon Rectal Surg. 2011;24(1):46–53. doi: 10.1055/s-0031-1272823. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Kumar M, Clay WH, Lee MJ, et al. A mapping review of sacrococcygeal pilonidal sinus disease. Tech Coloproctol. 2021;25(6):675–682. doi: 10.1007/s10151-021-02432-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Lee MJ, Strong EB, Lund J, et al. A survey of treatment preferences of UK surgeons in the treatment of pilonidal sinus disease. Colorectal Dis. 2023;25(10):2010–2016. doi: 10.1111/codi.16696. [DOI] [PubMed] [Google Scholar]
- 4.Strong E, Callaghan T, Beal E, et al. Patient decision-making and regret in pilonidal sinus surgery: a mixed-methods study. Colorectal Dis. 2021;23(6):1487–1498. doi: 10.1111/codi.15606. [DOI] [PubMed] [Google Scholar]
- 5.Wickramasekera N, Strong E, Shackley P, et al. Patient preferences for pilonidal sinus treatments: a discrete choice experiment survey. Colorectal Dis. 2023 doi: 10.1111/codi.16482.. [DOI] [PubMed] [Google Scholar]
- 6.Herrod PJ, Doleman B, Hardy EJ, et al. Dressings and topical agents for the management of open wounds after surgical treatment for sacrococcygeal pilonidal sinus. Cochrane Database Syst Rev. 2022;5(5):CD013439. doi: 10.1002/14651858.CD013439.pub2. [DOI] [PMC free article] [PubMed] [Google Scholar]