Pilonidal sinus - Treatment 

Incision and drainage

If you develop an infection inside a pilonidal sinus, you will need an operation to open the sinus up and drain away any pus, bacteria or other waste materials. This type of operation is known as incision and drainage.

You may be prescribed antibiotics to keep the infection under control while you wait to see a surgeon. However, antibiotics will not cure the pilonidal sinus.

Incision and drainage will usually be carried out at your local hospital. The procedure is most commonly performed under general anaesthetic, where you are asleep throughout the operation. As the incision and drainage procedure is relatively minor, you should be able to return home after you have recovered from the effects of the anaesthetic. This will usually be the same day as the operation.

After the operation, a dressing will be applied to the affected area to allow your skin to heal. You will need to arrange for your dressing to be changed daily by the practice nurse at your local GP surgery.

Treating recurring infection

If you have recurring infections in a pilonidal sinus, surgery may be recommended to remove the sinus and prevent further infections. The classic sign of a recurring infection is pain followed by swelling and then discharge.

The two main types of operation to remove a pilonidal sinus are:

• wide excision 
• excision and primary closure

Wide excision

During wide excision, the surgeon will cut out the section of skin that contains the sinus. The wound is left open and packed with a dressing.

The advantage of having a wide excision is that, after the procedure, the chances of the infection returning are low. The disadvantage is that the wound will take a long time to heal and your dressings will need to be changed daily for two or three months.

Excision and primary closure

In an excision and primary closure, the surgeon will cut out the section of affected skin before closing and sealing the wound with stitches. The advantage of this technique is that the wound will heal quite quickly. The disadvantage is that the chances of the infection returning are higher than with a wide excision.

The surgeon may remove the sinus from:

• the centre, between the buttocks (midline closure)
• away from the centre of the buttocks (off-midline surgical closure)

The off-midline surgical closure technique is considered to be better than the midline closure technique. This is because there is a better flow of air to the wound and it is easier to keep clean, so it tends to heal better.

Some studies have found that midline surgical wounds take around five days longer to heal, and there is a higher chance of the infection returning than with off-midline surgical wounds.

Possible off-midline surgical methods include:

• the cleft lip procedure, also known as Bascom’s procedure
• the rhomboid flap, also known as the Limberg flap
• the Karydakis flap 
• Z-plasty

These are different methods of using a flap of your own skin and tissue to fill and close the wound that is left after removing your pilonidal sinus. Your surgeon can explain the technique that they will be using in more detail.

Having surgery

Before deciding which type of operation to have, discuss the advantages and disadvantages of each technique with your surgeon.

Surgery may be carried out under:

• general anaesthetic - where you are asleep throughout surgery
• local anaesthetic - where the area is numbed 
• spinal anaesthesia - where the spinal nerves are numbed

During surgery, some surgeons insert a small drain, which is usually removed the following day.

You may feel some discomfort after your operation. The healthcare professionals looking after you should be able to provide pain relief. You may also be given painkillers to take at home after you have left hospital. You will usually be discharged on the day of your operation or, in some cases, the following day.

After your operation, you will probably need to take some time off work, although this will depend on how you are feeling and the type of work you do. Avoid strenuous work for up to two weeks.

You can start to exercise and do sporting activities as soon as you feel able to. However, if you have stitches, you may need to avoid activities that could disrupt the stitches for two to four weeks.

Wound care

Whatever type of surgical procedure you decide to have, it is very important that you keep the site of the wound clean after the operation. Your surgeon can give you advice about how to do this. This may include some of the following points:

• Have a shower or bath at least once a day if your wound is being left open and packed with a dressing. 
• If your wound is closed with stitches, avoid having a bath. You may be advised to keep the wound completely dry for the first few days. Ask your surgeon for advice. 
• When washing the wound, do not use soap because this will irritate your skin. Use plain water and a soft cloth instead. 
• Do not use talcum powder. 
• Use wet wipes to clean the area when you are away from home. 
• Carefully dry the area after washing using a soft towel, but do not rub the skin. Using a hair dryer is an effective alternative method of drying the area. 
• Always remove a damp or wet dressing and replace it with a dry, clean one. 
• Wear loose-fitting cotton underwear and avoid synthetic underwear, such as nylon. 
• Eat foods that are high in fibre, such as vegetables, fruit and bran flakes, because they will help to soften your stools and reduce any straining when you go to the toilet. 
• You will probably be advised to shave any hair growing near the site of the wound. It may be recommended that you shave this area even after the wound has healed to prevent the pilonidal sinus from returning.