What is pilonidal sinus?

Pilonidal means a ‘nest of hairs’. A pilonidal sinus is a small tunnel that develops at the top of the crease in the buttocks. Trapped hair around the buttocks crease can lead to an abscess, and a pilonidal sinus may develop as a result.

The cause for pilonidal disease is not completely understood but fallen hair often starts creating sinus in the cleft (crease) between the buttocks. These hairs can traumatize and penetrate the skin at the top of the buttock crease. Hairs can get caught under the skin in this area.  This can result in irritation, infection, and formation of an abscess.

Once the abscess heals, either on its own or with treatment, a pilonidal sinus may develop. The sinus is like a pipe just under the skin with tiny openings to the surface of the skin. People with a pilonidal sinus need to take care of the area to prevent future abscesses and infections.

What are the symptoms of a pilonidal sinus?

A pilonidal sinus affects the natal cleft, which is the top of the crease of the buttocks, just under the tailbone.

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.

If people have a pilonidal sinus, they may have the following symptoms:

• small dimple in the skin
• irritation or discomfort
• painful mass, which may be an abscess
• drainage from the area, which may be a clear, cloudy, or bloody fluid
• red, tender area
• foul-smelling pus
• fever

Causes

• Risk factors for pilonidal sinus include:
• being male
• having a family history of pilonidal disease
• being overweight
• experiencing trauma or irritation in the area
• having a sedentary lifestyle or sitting down for long periods
• having a lot of hair around the buttocks
• practicing poor hygiene habits
• being younger, as pilonidal sinus is more common in young adults

What is the treatment for pilonidal sinus?

If you have no symptoms

If you have no symptoms then you will normally be advised to clear the affected area of hairs (by shaving, etc) and to keep the area clean with good personal hygiene.

If you have rapid-onset (acute) symptoms

If you have an infection then you may be given some medicines called antibiotics. Painkillers (such as paracetamol and/or ibuprofen) may be very helpful to improve the pain. It may be that you need to have an emergency operation. This procedure punctures (incises) and drains the ball of pus with the surrounding skin infection (abscess). This is usually done in hospital. Whether it is an initial or recurring occurrence, first-line treatment of acute pilonidal disease with abscess is incision and drainage. This option is successful in 60% of patients with primary disease, with 40% requiring an additional procedure. Up to 40% of patients treated with incision and drainage will have a recurrence because of inadequate management of debris, epithelialization, granulation tissue, and sinus tracts.

 

If you have persistent (chronic) symptoms

In most cases, an operation will be advised. There are various operations which are done to cure this problem. Your surgeon will be able to give the details and the pros and cons of each operation. The options include the following:

 

Pit picking

Reducing the abscess can help make the pilonidal sinus more visible and easier to treat.

A few weeks after abscess drainage, people may have a procedure called pit picking. People will have a local anaesthetic and a doctor will cut out the pit, or sinus.

 

Wide excision and healing by secondary intention. This operation involves cutting out (excision of) the sinus but also cutting out a wide margin of skin which surrounds the sinus. The wound is not closed but just left open to heal by natural healing processes (healing by ‘secondary intention’). This usually requires several weeks of regular dressing changes until it heals fully. The advantage of this method is that all inflamed tissue is removed and the chance of the condition coming back (a recurrence) is low.

Excision and primary closure. This means taking out 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. The two sides of the ellipse are then stitched together. The advantage for this is that, if successful, the wound heals quite quickly. The risk of a recurrence or of developing a wound infection after the operation is higher than with the above procedure. This risk may be reduced by using a wound technique in which the line of stitches is moved away from between the buttocks.

A plastic surgery technique. In some cases, where the sinus recurs or is extensive, plastic surgery may be advised to remove the sinus and refashion the nearby skin.

There are variations on the above procedures, depending on your circumstances, the size and extent of the sinus, and whether it is a first or recurrent problem. Your surgeon will be able to discuss with you in detail the most suitable type of operation.

New techniques are being researched to try to improve the recovery after having an operation.

Surgery 

Surgery is the most reliable method for treating and removing a pilonidal sinus, but it can come with possible complications, such as poor wound healing.

To open, or unroof, a pilonidal sinus, a surgeon will open up the abscess and sinus, and trim any edges of the skin. A surgeon may also remove any inflamed tissue surrounding the area.

A surgeon will then use healthy tissue to close the area. This method may carry a higher risk of infection, but it may be necessary in some cases.

People can discuss surgical options with their doctor to find out which may be the best choice for them, and any possible risks or side effects.

Complex or recurring infections are treated surgically, either through excision or unroofing (opening) the sinuses. Unroofing the sinuses, as shown in Figure B, involves opening up the abscess and tracts and trimming the edges of skin

Drawing B shows inflammation located deep under the skin above the tailbone. The dashed line indicates the area to be opened or unroofed. The dashed line in drawing C shows the entire inflamed tissue that will be removed.

>Operations with complete excision of tracts and any abscess cavity often result in better long-term outcomes, although healing takes longer. Closure with flaps (moving healthy body tissue into the area) has a greater risk of infection, but may be required in some patients. Your colon and rectal surgeon will discuss all the options and help you choose the most appropriate surgery.

POSTSURGICAL PROGNOSIS

If people have surgery, they will usually be able to return home the same day as their operation. Depending on how people respond to surgery, they may be able to return to work within 2–3 weeks.

People can talk with a doctor about when it is safe for them to return to exercise and regular activities again.

When the wound is closed, it must be kept clean, dry and free of hair until the skin is fully healed. If the wound is left open, dressings or packing are used to help remove secretions and allow the area to heal from the bottom up.

After healing, the skin in the buttocks crease must be kept clean and free of hair. It is necessary to shave or use a hair removal agent every 2 or 3 weeks until the age of 30. After that age, hair shafts thin out and soften and the depth of the buttock cleft lessens. Pilonidal disease can be a chronic, recurring condition so it is important to follow your physician’s postsurgical care instructions.

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Complications

In severe cases, a pilonidal sinus may result in Complication. People may have an infection that spreads, or they may have a secondary infection.

Surgery may also lead to complications, such as:

• poor wound healing
• numbness around the wound
• bleeding
• pain
• possible scarring
• infection of the surgical site
• blood clots

In rare case, pilonidal sinus may have a link to osteomyelitis, swelling or inflammation of the bone, or skin cancer.

Prevention

Overall, the outlook for pilonidal sinus is very good and rarely has any long-term harmful effects.

A pilonidal sinus can return after treatment, but maintaining good hygiene habits and removing hair from the area may help reduce the risk of it returning.

Hair removal

In minor cases, hair removal may be the first step in preventing a recurrent pilonidal sinus infection.

Hair removal options may include:

• shaving
• waxing
• laser removal
• epilation creams

Research suggests that regular hair removal and maintaining good hygiene of the area may result in reduced surgical procedures and being able to return to normal activities. However, in some cases, hair removal increased pilonidal recurrence.

People will need to take care with certain hair removal techniques, as some may cause irritation or rashes.

Summary

A pilonidal sinus is a small tunnel under the skin above the buttocks crease. It can develop when hairs or a hair follicle get trapped deep into the skin. Inflammation and abscess formation can be painful, but treatment is usually successful.

Treatment options include abscess drainage and surgical removal of the sinus, followed by frequent hair removal to help prevent future issues.

Book your appointment at the earliest with our specialists at Piles clinic UK.