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:. 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.
