A pilonidal cyst is a small pocket in the skin, which contains hair and skin debris. Pilonidal cysts usually occur in the groove-like area where the buttocks divide (the natal cleft). The pilonidal disease includes a ‘pilonidal cyst’, as well as a ‘pilonidal sinus’ which is a small tunnel in the skin.1
The name ‘pilonidal’ has derived from Latin, where the meaning of ‘pilus’ is ‘hair’, and ‘nidus’ means ‘nest’. This condition was named by R. M. Hodges in 1880 but was first described earlier by O. H. Mayo in 1833. The pilonidal disease has also been documented as “jeep disease”, as it used to be quite prevalent among U.S. soldiers during wartime.2
Pilonidal cysts or sinuses are most commonly situated at the top of the buttock crease, close to the tailbone. However, it can also affect other areas of the body such as the axilla, groin, scalp, and in the cleft between fingers.
Pilonidal disease is known to affect people assigned male at birth (AMAB) 2.2. times than people assinged female at birth (AFAB). Pilonidal disease is diagnosed in about 26 per 100,000 people per year.1
Causes of pilonidal cysts
A pilonidal cyst is described as a condition caused by the ingrowing of loose hairs into the skin at the top of the buttock crease, leading to the formation of a long-lasting tunnel or a cavity. Frequent rubbing of thick, stiff hairs over the area of the buttocks caused by pressure or friction is thought to be the underlying cause of the development of pilonidal cysts.1
You have a high risk of developing a pilonidal cyst if you have the following factors:3
- Age between 15 to 40
- White ethnicity
- Excessive body hair growth (Hirsutism)
- Thick and stiff body hair
- Overweight or obesity
- Occupations involving long periods of driving, cycling, or sitting
- Tight clothing
Signs and symptoms of pilonidal cysts
A pilonidal cyst usually does not cause any symptoms, unless an infection has settled in. Because of this reason, pilonidal cysts often go unnoticed, until they become infected and painful. When infected, a pilonidal cyst or sinus can lead to a pilonidal abscess, which is a painful collection of pus or an infected pilonidal sinus.
Following are the usual symptoms caused by a pilonidal abscess:4
- Swelling or a lump beneath the skin
In addition to the above symptoms, an infected pilonidal sinus may cause symptoms such as:
- Pus discharge from the pilonidal sinus
- An unpleasant odour from pus
- Bleeding from the pilonidal sinus
Generally, the symptoms of a pilonidal abscess or an infected pilonidal sinus develop over a few days. These symptoms indicate underlying infection, therefore need to be treated by a General Practitioner (GP).
Management and treatment for pilonidal cysts
The diagnosis of the pilonidal cyst is made from your history and examination alone by your General practitioner. No additional investigations are required for the diagnosis of this condition.5
Management of Pilonidal cyst which is not infected
The ‘Watch and wait’ approach is recommended if your pilonidal cyst is not infected.
Keeping the affected area, between your buttocks clean by washing and showering regularly will help the recovery.
However, do not try to shave the affected area unless you are advised by your medical practitioner to do so.4
Management of Infected pilonidal cyst/ Pilonidal abscess
There are several treatment options to treat the pilonidal abscess. Your GP will decide the best option of treatment based upon the following factors:4
- The size of the sinus or cyst
- Symptoms you have
- Recurrence of the condition, whether this is the first incidence, or whether it keeps coming back
Antibiotics will be offered in all infected pilonidal cysts to help fight the infection. Along with the antibiotics pain killers will be prescribed to you to alleviate pain.
In addition to antibiotics, there are a few surgical options that you will be offered.
Minor surgery to drain pus from the infected sinus
Your doctor will use the terms ‘incision and drainage’ or ‘I and D’ when explaining this procedure.1
This is done within a hospital setting for uncomplicated abscesses. A small cut will be made on the abscess, so that the pus inside it will be drained out.
This is done under general anaesthesia where you will fall asleep during the time of the surgery or under local anaesthesia where your affected area will be made numb by injecting some drugs into the surrounding area. You are allowed to leave on the same day. You will need to change the dressing daily and keep the area clean. It will usually take around 4 to 6 weeks to heal the wound completely.
Sinus removal (Open wound)
You will be offered this option if you have a large infected pilonidal sinus or a recurring one. The sinus will be cut out and part of the surrounding tissues will be removed during the surgery. The wound will be kept open to heal naturally.1
This surgery is done under general anaesthesia. You will be able to leave the hospital on the same day most of the time. You will need to change your dressing frequently. This will take around 6 to 12 weeks to heal completely.
Sinus removal (Closed wound)
You will be offered this option if you have a large infected pilonidal sinus or a recurring one. The sinus is completely removed and infected tissue will be removed. Then two skin flaps from the surrounding skin are cut out on either side of the sinus, in an oval shape. The 2 skin flaps will be stitched together.1
This surgery is done under general anaesthesia. You will be able to leave the hospital on the same day most of the time. The stitches will be removed about 10 days after the surgery. This surgery carries a higher risk of reinfection which requires reopening of the wound.
Endoscopic ablation / Endoscopic Pilonidal Sinus Treatment (EPSiT)
An endoscope, which is a long thin flexible tube with a camera at the end is used to obtain a clear view of the affected area. Then hair and infected tissues will be removed, and the pilonidal sinus will be cleaned using a special solution. Finally, heat will be applied to seal the sinus.6
This procedure is done under spinal or local anaesthesia. This procedure does not require cuts and reports to have a good success rate with fewer complications. Usually, takes around one month to heal.
How common are pilonidal cysts
It is estimated that pilonidal disease is diagnosed in 26 per 100,000 people each year (incidence). Pilonidal disease is more common among AMAB than AFAB. It is reported to affect AMAB 2.2 times more than AFAB.
Who are at risks of pilonidal cysts
People with excessive, thick, stiff body hairs and subjected to long-standing pressure or friction over their buttocks are at the most risk of developing pilonidal cysts. Therefore, AMAB, young age between 15 to 40 years, white ethnic group, presence of excessive body hair (hirsutism), being overweight, having tight clothing, and having jobs that require long hours of sitting, cycling, or driving are identified as risk factors of pilonidal cysts.
How is pilonidal cyst diagnosed
This condition will be diagnosed by your doctor based on the history (symptoms) and examination (signs).
How can I prevent pilonidal cyst
Pilonidal cysts may be prevented by maintaining the following hygienic practices and adopting a healthy lifestyle to have a body weight within the healthy range.
- Washing the buttock area regularly
- Avoiding long hours of sitting
- Maintaining a healthy body weight by healthy eating and regualr exercise
When should I see my doctor
If you have symptoms of a pilonidal abscess like, pus coming out from the cyst, unpleasant odour, or bleeding from the sinus, you should see your doctor.
A pilonidal cyst is a small pocket in the skin, which contains hair and skin debris. Pilonidal cysts usually occur in the groove-like area where the buttocks divide. Usually, these get healed without treatments.
However, sometimes pilonidal cysts can get infected and converted into pilonidal abscesses that require treatment with antibiotics and surgical treatments.
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- Pilonidal cyst and sinus - statpearls - NCBI bookshelf [Internet]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557770/
- Doll D, Brengelmann I, Schober P, Ommer A, Bosche F, Papalois AE, et al. Rethinking the causes of pilonidal sinus disease: a matched cohort study. Sci Rep [Internet]. 2021 Mar 18 [cited 2023 Jun 8];11(1):6210. Available from: https://www.nature.com/articles/s41598-021-85830-1
- Khanna A, Rombeau J. Pilonidal disease. Clinics in Colon and Rectal Surgery [Internet]. 2011 Mar [cited 2023 Jun 11];24(01):046–53. Available from: http://www.thieme-connect.de/DOI/DOI?10.1055/s-0031-1272823
- Otutaha B, Park B, Xia W, Hill AG. Pilonidal sinus: is histological examination necessary? ANZ Journal of Surgery [Internet]. 2021 Jul [cited 2023 Jun 11];91(7–8):1413–6. Available from: https://onlinelibrary.wiley.com/doi/10.1111/ans.16446
- Mahmood F, Hussain A, Akingboye A. Pilonidal sinus disease: Review of current practice and prospects for endoscopic treatment. Annals of Medicine and Surgery [Internet]. 2020 Sep 1 [cited 2023 Jun 11];57:212–7. Available from: https://www.sciencedirect.com/science/article/pii/S2049080120302326