Coccyx Fistula: what it is, causes, symptoms and treatments

• Coccygeal fistulas are often called pilonidal sinus, although they may also be called pilonidal cyst or sacral cyst.
• Coccygeal fistulas can be single or multiple and in most cases will require surgery to remove them.
• A coccygeal fistula is usually diagnosed by a doctor based on the patient's symptoms.

A fistula is an abnormal area of connection between the intestine or any organ, and another area of the body.

When the fistula develops in the coccyx area we call it a "pilonidal sinus", although it is also known as a "pilonidal cyst" or "sacral cyst", among others. It is a gap that develops around a hair follicle.

The fistula in the coccyx may be single or multiple. Usually the cyst expands upwards, towards the outside of the skin, but on some rare occasions it expands downwards, towards the anal area, where it can produce an anal fistula.

It is a fairly common pathology, which is not dangerous for the patient, but it is annoying for day-to-day activities.

It is found in men and women of all ages, but is most common in men between 15 and 30 years of age.

A coccygeal fistula usually has no symptoms and is usually discovered by chance when redness and swelling in the coccygeal area are observed.

The problem comes when the fistula in the coccyx becomes infected, often due to skin bacteria that tend to accumulate in that area. 

Once the fistula in the coccyx is infected, an abscess is produced and the most frequent symptoms are:

• Pain and warmth in the coccyx area.
• Swelling and redness.
• High fever.
• Abscess and spontaneous drainage of the abscess.
• General discomfort, including muscle and joint pain.

Even if the coccyx fistula is infected, it does not necessarily present all the symptoms, it may present one or two or even none at all if the infection is not very advanced.

Usually the diagnosis of a coccyx fistula is clinical, based on the symptoms explained by the patient, and a brief physical examination is usually sufficient. The patient's family and personal history that may have favoured the development of the coccyx fistula is also usually taken into account.

The appearance of a fistula in the coccyx can occur for various reasons, although the most frequent is the encystment of a hair, which penetrates the subcutaneous tissue and, due to the presence of a foreign body, the organism begins to generate a cyst around it to "protect" the inside of the body from this foreign element.

There are some situations that can lead to the appearance of a fistula in the coccyx, for example:

• Excess body hair.
• Sedentary lifestyle.
• Excessive sweating.
• Suffering from folliculitis.
• Obesity.
• Wearing very tight clothing.
• Trauma to the area.

Non-surgical treatment

If the fistula in the coccyx is not infected, non-surgical treatment can be performed to end the fistula. The treatment consists of removing the hair around the cyst, preferably with a laser.

Surgical intervention

It is possible to alleviate the symptoms of a coccyx fistula infection by means of painkillers, antibiotics and various creams, but when the coccyx fistula has become infected, the only possible solution to end the problem is surgery.

This is often quite aggressive surgery, as it is necessary to remove the entire area that may be affected to prevent the infection from reproducing once it has been removed.

Usually, surgical interventions to eliminate coccyx fistulas are performed on an outpatient basis, and the patient is discharged on admission, having to undergo routine check-ups a few days after the intervention.

There are several types of surgery to eliminate a coccyx fistula, although the most common is the one described below:

Incision and drainage, leaving the wound open

Local anaesthetic is applied, then a small incision is made through which the wound is drained. The hair follicles are then removed and gauze is placed over the wound to isolate the wound from environmental bacteria.

The wound is left open, in the sense that no stitches are used, so that it closes on its own, allowing the tissues to grow and gradually close the wound. The postoperative period for this technique is quite long, lasting up to 4 weeks.

After surgery

As these are outpatient operations, the patient can leave the hospital on the same day as the operation.

As with any surgical wound, it is necessary to take great care with it in order to speed up recovery and keep it as short as possible. In this aspect, the hygiene of the wound is fundamental, as any type of infection will probably lengthen the recovery; it is essential to wash the wound and heal it, your doctor will tell you what steps to follow to do this correctly.

The doctor will also give instructions on how and how often to change the wound dressings and will probably prescribe medication to combat possible pain after the operation.

A couple of days after surgery, you will need to have a routine check-up to make sure that the wound is progressing well and that there are no complications.

Surgical intervention for the elimination of a coccyx fistula is relatively simple, so it rarely presents complications and when it does, they are of a mild or moderate nature and can be corrected without any type of problem.

Some of the possible complications that may occur after surgery are:

• Wound infection.
• Wound bleeding.
• Allergic reaction to medication.
• Reappearance of the fistula in the coccyx.
• Poor wound healing.