Coccygeal fistula: causes and symptoms

When ingrown hair causes pain

Causes and risk factors

In the meantime, we have set up a separate page for our treatment focus on sinus pilonidalis. The updated and more detailed information on causes and risk factors of coccygeal fistula can be found here. 

A coccyx fistula - also called sinus pilonidalis - is an inflammation of the gluteal fold. This is usually caused by hair roots filled with ingrown hair. If a hair grows inwards instead of outwards, broken hair and keratin scales are brought under the skin surface. In this way, small nodules (medical granulomas) are formed which can be inflamed by bacteria.

  • One reason for the development of a coccyx fistula can be disturbed hair development. A newly growing hair is not properly pushed out of the hair root. The building material of the hair, keratin, is accumulated in the form of bulbous deposits in the hair root (follicle).
  • Even if the hair is formed normally, a pilonidal sinus can occur. Namely, when hairs break and impale themselves into the wall of the hair follicle. The follicle fills with broken hairs.
  • Loose hair from the back or head can also be massaged into the buttock crease by the constant movements of the buttocks. The surface structure of the hairs, similar to a barbed arrow, causes hairs once impaled to remain stuck in the tissue and cannot be removed even by washing.
  • A final cause may be a phenomenon sometimes seen in fistula tracts that have already been removed: It seems as if hair has grown directly "underground", probably as a result of a developmental disorder. Here, too, a coccygeal fistula is the result.

In any case, the extended hair follicle is always recognizable as a small black dot or as an opening the size of a millimeter. If one sees such a pit, the diagnosis of a coccyx fistula is confirmed.

Besides ingrown hairs, very rarely congenital malformations of the coccyx or occasionally bruises after a fall can be responsible. Men are affected by coccygeal fistulas about twice as often as women and usually become ill between the ages of 20 and 30. In addition, there are other factors that can favour coccygeal fistulas:

  • Strong hair growth
  • Continuous sitting
  • Strong sweating and underwear that is too tight
  • Insufficient hygiene
  • overweight
  • Weakened immune system

Be sure to stand up more often if you have to sit for long periods and prefer well-padded chairs. If you are prone to strong hair growth, preventive laser hair removal in the coccyx area can be useful.

Coccyx fistula: Symptoms

But how do you recognize a coccyx fistula exactly? Basically, there are three stages of inflammation, which are associated with different symptoms:

  • Bland form: The development of a coccygeal fistula is not noticed at first or the complaints are minor and non-specific (pain when sitting on hard chairs, feeling like a "pimple" or a bruise). Sometimes, apart from a visible opening in the area of the buttock fold, there are no complaints at all.
  • Acute form: A pilonidal abscess can develop within a few days, the underlying coccyx fistula already existed unnoticed before. The typical characteristic with a reddened, painful bump at the bottom or in the coccyx region can be recognized at a glance. The externally visible symptoms may be minor. The patient's in a lot of pain, even though you can't see much. On closer inspection, a hardening can be felt and the skin appears conspicuous. The pits are often not visible due to swelling. Sometimes patients report a previous fall on the coccyx. A causal connection cannot be explained. It is not uncommon for complaints to occur after long periods of sitting, as with schoolchildren and office workers or after long flights.
  • Chronic form: Some patients have only mild pain and notice the presence of the fistula only accidentally or due to the secretion of blood or pus. The colonisation of the pilonid fistula by the bacteria always present in this region can cause a very unpleasant odour development. The capsule often contains many collagen fibres and feels hard like cartilage, so that irritations occur when sitting for long periods without any actual pain. Sometimes the patients themselves discover small openings in the area of the gluteal fold.

No matter what symptoms you notice: Go to the doctor! The earlier a coccyx fistula is detected, the better it can be treated.

Sinus pilonidalis: Prevention

To prevent an unpleasant coccyx fistula from developing in the first place, there are tips that you can follow. Since a pilonidal sinus is usually caused by ingrown hair, permanent removal of the hair in the coccyx region is the best way to prevent the disease. With a diode laser, the hair can be lasered away painlessly, quickly and long-lastingly. If you sweat a lot and wear tight underwear, the risk of a coccyx fistula also increases. Long periods of sitting on a hard surface and overweight should also be avoided.

In our proctological practice in Munich we are there for you if you have any questions on the subject of coccyx fistula.


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