A pilonidal sinus is a small hole or “tunnel” in the skin. It usually develops in the cleft of the buttocks where the buttocks separate.
More than one hole may develop, and often these are linked by tunnels under the skin. Most people associate the word sinus with the nose, but sinuses can occur anywhere in the body. Sinus is simply a medical term for a channel or cavity.
A pilonidal sinus will not usually cause any noticeable symptoms unless it becomes infected. This can cause a pus-filled abscess to develop. Signs that you may have an infection include pain, redness and swelling in the affected area. If a pilonidal sinus becomes infected, it should be treated as soon as possible, as it’s likely to get worse. Treatment usually involves taking antibiotics and having the pus drained from the abscess during a minor operation called incision and drainage. If the sinus keeps becoming infected, it may have to be surgically removed. Several techniques can be used, including:
- cutting out the sinus and leaving the wound open so it can heal, and packing it with a dressing daily
- closing the wound with a flap of skin and stitches
- scraping out the sinuses and filling them with a special glue