Pilonidal means a 'nest of hairs'
A sinus tract is a small abnormal channel (a narrow tunnel) in the body. A sinus tract typically goes between a focus of infection in deeper tissues to the skin surface. This means that the tract may discharge pus from time to time on to the skin.
A pilonidal sinus is a sinus tract which commonly contains hairs. It occurs under the skin between the buttocks (the natal cleft) a short distance above the anus. The sinus track goes in a vertical direction between the buttocks. Rarely, a pilonidal sinus occurs in other sites of the body.
A pilonidal sinus may not cause any symptoms at first. 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'.
Pain and swelling develop over a number of days as an infected abscess develops in and around the sinus. This can become very painful and tender.
Around 4 in 10 people have a recurrence of their pilonidal sinus. 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 then can mean that the symptoms of pain and discharge can persist long-term, or flare up from time to time, until the sinus is treated by an operation.
If you have an infection then you may be given some 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 to incise (puncture) and drain the abscess.
In most cases, an operation will be advised. There are various operations which are done to cure this problem. There are pros and cons of each operation. The options may include the following:
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.