The hair between the buttocks can be pushed inwards due to a  skin problem, pressure or friction. This can either be hair growing around the buttock area, or loose hair shed that stays in the buttocks or elsewhere that gathers around the buttock cleft and enters the pilonidal sinus.

Pilonidal sinuses are common in adults over the age of 40, especially in men. The cause of a pilonidal sinus is not clear; it may be due to prolonged sitting that causes friction and forces the hair growing in the buttocks to curl over.

The inward growth of hair instead of the original upward direction leads to the development of Pilonidal sinus. The hair gets stuck inside the skin, causing irritation. This prolonged irritation causes the skin to become infected. Pus formation can occur once the infection sets in and a sinus develops which consists of the hair that opens onto the surface of the skin.

In the initial stages, a pilonidal sinus does not present any symptoms apart from a lump that may be felt between the buttocks during a wash. In some instances however, symptoms develop that can be acute or chronic.

The signs and symptoms of a pilonidal sinus include the following: 

1. Pain, redness and swelling
2. Foul-smelling pus
3. Blood draining out from the sinus
4. Hair protruding from the lesion
5. More than one sinus tract, or holes formation on the skin

The diagnosis is conducted with a complete physical examination. During the examination, the doctor checks the crease of your buttocks for signs of a pilonidal cyst. If you have a pilonidal cyst, it should be visible to the naked eye.

The doctor will then diagnose a pilonidal sinus based on the signs. The signs of infection include:

1. Cyst becomes larger, filled with pus and hair
2. An abscess which keeps discharging pus
3. Pain present while sitting or standing
4. High-grade fever
5. Hair protrudes out from the sinus
6. More than one sinus tract is found on the skin on examination

If you have undergone an open surgery, you will need to change the dressing over the cut regularly. This can be done at the doctor’s clinic or by yourself. The wound should be cleaned once a day before the new dressing is applied. You may choose to take a warm bath to clean your wounds; remember to not add scented shower gels or other perfumed products to your bath until the wound has healed completely.

In the closed method, it is advised to keep the area clean and dry until the stitches are removed. To prevent pilonidal sinus from recurring, keep the desired area free from hairs and clean it regularly to avoid the risk of infection.

You can resume office work after 10 days to 2 weeks after the treatment. Regular exercise will speed up the recovery and help you to return to normal activities at the earliest. Check with your doctor before you start exercising.