Pilonidal cyst is a swelling that starts under the skin on the sacrum near the tailbone resulting in fistula formation. Although the exact causes of cyst formation has not yet been accurately determined, it is believed that this is due to an infection caused by hair follicle inflammation – folliculitis that progresses over time leading to a larger subcutaneous abscess.
Pilonid cysts can be acute and chronic. Acute pylonid cyst is associated with pain, redness, and swelling in the tailbone area with possible accompanying fever. Painful infiltrate is usually observed in the intergluteal cleft asymmetrically to the midline.
Chronic pylonid cyst is usually diagnosed accidentally after the cyst becomes infected and causes symptoms, such as fluid discharge from one or more abscesses.
Cysts can be treated using the conservative method of carefully shaving the intergluteal area and strictly obeying hygiene rules, however, when the conservative treatment is ineffective, the cyst can be removed surgically.
The surgery is performed under spinal or general anesthesia, and it usually takes an hour to complete. The method of the surgery depend on the size and type of the cyst (chronic or acute).
In case of acute cyst, a small hole is made in the abscess so the pus can be drained. Sometimes the drain is left inside the opening for some time. In case the cyst is chronic, an incision is made in the area of the cyst and fistula channel, and the fistula channel is thoroughly cleaned.
Both acute and chronic pilonid cysts may recur and require another surgery to remove them. On average, recurrences after scheduled surgery range from 3% to 10% and are usually due to poor post-operative wound care with hair growing into the scar.