A pilonidal sinus is a small pit that occurs at the bottom of the tailbone or coccyx that can become infected and filled with pus. Pilonidal means a ‘nest of hairs’.
Sinus tract is a abnormal narrow tunnel in the body which goes between a focus of infection in deeper tissues to the skin surface. This channel discharges pus occasionally on the skin.
Pilonidal tract is a sinus tract which contains hairs. It appears under the skin between the buttocks (the natal cleft) a short distance above the back passage (anus). It goes in a vertical direction between the buttocks.
However, in some rare cases, pilonidal sinus can appear in other parts of the body.
WHAT IS A PILONIDAL SINUS?
Pilonidal means a ‘nest of hairs’.
A sinus tract is a narrow tunnel (a small abnormal channel) in your body. A sinus tract typically goes between a focus of infection in deeper tissues to your skin surface. This means that the tract may discharge pus from time to time on to your skin.
A pilonidal sinus is a sinus tract which commonly contains hairs. It occurs under your skin between your buttocks (the natal cleft) a short distance above your back passage (anus). The sinus tract goes in a vertical direction between your buttocks. Rarely, a pilonidal sinus occurs in other sites of your body.
WHAT CAUSES A PILONIDAL SINUS?
The exact cause is not clear. There are various theories. For example, one theory is that the problem may develop from a minor abnormality you were born with, in the skin between the buttocks. This may explain why the condition tends to run in some families. Part of the abnormality in this part of your skin may be that the hairs grow into your skin rather than outwards.
Another theory is that you develop skin dimples (skin pits) in the skin between your buttocks. These may develop as a result of local pressure or friction causing damage to the small structures below your skin which are responsible for making hairs (the hair follicles). Because of local pressure, growing hair in your natal cleft may become pushed into your skin pits.
Whatever the cause, once hair fragments become ‘stuck’ in your skin they irritate it and cause inflammation. Inflamed skin quickly becomes infected and so a repeated (recurrent) or persistent infection tends to develop in the affected area. The infection causes the sinus to develop which often contains broken pieces of hair.
(A similar condition can occur between the fingers of hairdressers, caused by customers’ hairs entering moist, damaged skin.)
WHO GETS PILONIDAL SINUS?
Certain factors increase the risk of developing the condition and include:
-A job involving a lot of sitting (a sedentary occupation)
-Being overweight (obesity)
-A previous persistent irritation or injury to the affected area
-Having a hairy, deep natal cleft
-A family history of the condition
WHAT ARE THE SYMPTOMS OF A PILONIDAL SINUS?
A pilonidal sinus may not cause any symptoms at first. You may not be aware that you have one. Some people notice a painless lump at first in the affected area when washing. However, in most cases, symptoms develop at some stage and can be ‘acute’ or ‘chronic’.
RAPID-ONSET (ACUTE) SYMPTOMS
You may develop increasing pain and swelling over a number of days as a ball of pus with surrounding skin infection (an infected abscess) develops in and around the sinus. This can become very painful and tender.
PERSISTENT (CHRONIC) SYMPTOMS
Around 4 in 10 people have a repeated (recurrent) pilonidal sinus. You may develop some pain which is less intense than the acute symptoms. Usually the sinus discharges some pus. This releases the pressure and so the pain tends to ease off and not become severe. However, the infection never clears completely. This can mean that the symptoms of pain and discharge can last long-term, or flare up from time to time, until the sinus is treated by an operation.
WHAT IS THE TREATMENT FOR PILONIDAL SINUS?
IF YOU HAVE NO SYMPTOMS
If you have no symptoms then you should clear the affected area of hairs by shaving or other means of hair removal. Also, keep the area clean with proper personal hygiene.
IF YOU HAVE RAPID-ONSET (ACUTE) SYMPTOMS
If you have an infection then you should take antibiotics. Painkillers (such as paracetamol and/or ibuprofen) may be very helpful to relieve the pain. Maybe you will need to have an emergency operation to puncture (incise) and drain the ball of pus with surrounding skin infection (abscess).
IF YOU HAVE PERSISTENT (CHRONIC) SYMPTOMS
Generally, an operation is recommended.. The options include the following:
Wide excision and healing by secondary intention. This operation consists of cutting out the sinus but also cutting out a wide margin of skin which surrounds the sinus. The wound is left open to heal by natural healing processes (healing by ‘secondary intention’). This usually requires several weeks of regular dressing changes until it heals completely. The advantage of this method is that all inflamed tissue is removed and the chance of the condition coming back (recurrence) is low.
Excision and primary closure. This means removing the section of skin which contains the sinus. This is done by cutting out an oval-shaped (ellipse) flap of skin either side of the sinus, which takes out the sinus, and stitching together the two sides of the ellipse. After this the wound heals very The risk of a recurrence or of developing a wound infection after the operation is higher than the above procedure.
A plastic surgery technique. Sometimes, when the sinus recurs or is extensive, plastic surgery may be advised to remove the sinus and refashion the nearby skin.
After any operation
Surgeons recommend keeping the area free of hair growing by shaving regularly, or by other methods to remove the hair. This prevents the coming back (recurring) of the problem.