Pilonidal Sinus

What is a pilonidal sinus?

In a pilonidal sinus, broken hairs grow into the skin of the gluteal fold. This fold is located in the coccyx region at the transition from the back to the buttocks. Pressure and movements drive the hair further and further into the subcutaneous fatty tissue. They become encapsulated and a cyst forms, which causes inflammation in the skin. If the area around the hair becomes infected with bacteria, a purulent abscess forms, which can sometimes become very large.

Many terms for one clinical picture – what is what?

The clinical picture of inflammation caused by hair penetrating the subcutaneous fatty tissue has many different names. The correct medical terms are pilonidal sinus, pilonidal sinus, hair nest fistula or hair nest dimple. The last term is derived from the Latin: pilus (hair), nidus (nest) and sinus (bay). These three words basically describe the disease very well.

Pilonidal sinus occurs in three forms

Initially the coccyx fistula often causes no symptoms and therefore remains undetected. Doctors refer to this as symptom-free pilonidal sinus. Visually, only a small opening resembling a pore can be seen at the point where the hair has penetrated. Usually one or two such openings are formed. This form can persist for months, years or even for life.

However, if the inflammation spreads and the tissue becomes infected, a purulent abscess develops. The technical term for this is acute pilonidal sinus. The coccyx fistula then makes itself felt through some very unpleasant symptoms, above all pain and swelling. Sitting and lying on the back is then hardly possible. Fistulas also form. These are small ducts in the skin that normally have no business being there. They make their way to other tissues and organs, often branch out widely and usually contain a secretion. This fluid then flows out of the body in abnormal places.

Pilonidal sinus fistula can also take a chronic course(chronic pilonidal sinus). Those affected may feel less pain, but the abscess continues to secrete fluid mixed with blood and pus.

Acute and chronic coccyx fistula is treated by surgery. There are various surgical options with which surgeons can achieve success. Which procedure is used depends on the size and extent of the coccyx fistula.

Pilonidal sinus – frequency and age

Pilonidal sinus is a relatively common condition. In Western Europe, around 25 to 30 out of every 100,000 inhabitants contract the disease. But the number of cases is rising for unknown reasons. The clinical picture usually occurs between the ages of 20 and 30. Men are affected by pilonidal sinus more than twice as often as women.

Pilonidal sinus: causes and risk factors

Researchers now assume that pilonidal sinus is an acquired disease that only occurs in the course of life. This is also supported by the fact that the disease occurs not only in the coccyx region, but also in other parts of the body. Examples are the navel, breast, penis or the creases between the fingers of hairdressers. Doctors used to assume that pilonidal sinus could also be congenital and that the fistulas were caused by an error in the development process of the unborn child. However, this theory has largely faded into the background.

Pilonidal Sinus – Causes are penetrated hairs

The causes of pilonidal sinus are broken hairs that penetrate the skin at the gluteal fold. The fact that the horny scales of the hair serve as barbs is conducive to penetration into the subcutaneous fatty tissue. The pressure on the skin when sitting and movements ensure that the hair is pushed further and further into the skin and irritates it. The skin reacts to the hair as if it were a foreign body and triggers an inflammation. A cyst forms around the hair, which contains hair fragments, granulation tissue (formed during wound healing) and dead cell remnants. Sometimes the cyst does not cause any symptoms. Doctors call this asymptomatic pilonidal sinus.

In many cases, however, the cyst becomes infected and a purulent abscess develops, which sometimes takes on larger dimensions (like a plum or tangerine). However, those affected usually do not realize how large the abscess in the subcutaneous fatty tissue actually is. Fistulas, i.e. unnatural passages in the tissue, also develop. These usually make their way out and drain the purulent, bloody secretion that comes from the abscess.

Risk factors for pilonidal sinus

We know or discuss some risk factors that favor the occurrence of a pilonidal sinus. These include, for example:

• Age: The disease occurs more frequently in people between the ages of 20 and 30.
• Familial predisposition: Some studies have found a familial clustering of the disease.
• Heavy body hair: The likelihood of hair breaking off is increased.
• Overweight and obesity (adiposity), thick subcutaneous fatty tissue
• Deep buttock crease, large buttocks
• Skin disease acne inversa
• Heavy sweat production, especially during puberty
• Frequent sitting in everyday life and at work, for example at a desk, in the car or at home
• Wear tight, air-impermeable clothing
• Lack of personal hygiene, especially in the anal area

Symptoms: Pilonidal sinus can become very painful

Whether and which symptoms a pilonidal sinus causes depends on how it manifests itself. There is also a form that does not cause any symptoms and therefore often goes unnoticed (asymptomatic pilonidal sinus). Sometimes doctors discover the disease by chance. Treatment is usually not necessary.

However, the cyst often becomes infected and an abscess develops within a few days, which can vary in size (acute form).

The following symptoms can occur with an acute pilonidal sinus:

• Fever, chills, general feeling of illness
• Pain in the area of the coccyx, which can sometimes be very severe – the fistula tract is blocked and secretions build up.
• The skin in the affected area reacts sensitively to pressure.
• Skin redness
• Swelling of the skin above the gluteal fold, which feels soft when you press on it
• Overheating of the affected skin area
• secretion of pus or blood from a small opening in the skin, the secretion often has a foul, foul odor
• Pain when sitting or lying on the back

Sometimes the disease is chronic. The following symptoms are typical of a chronic pilonidal sinus:

• There is usually no pain or swelling because the fistula tract is open and the secretions can drain away.
• A fluid containing blood and pus sometimes or permanently runs out of a small opening.
• Some people notice a feeling of pressure, the intensity of which can vary.

Always consult a doctor if you experience pain, skin changes or fluid secretions in the coccyx region – even if it may seem uncomfortable. She or he can find out what is behind the complaints.

Pilonidal sinus: Diagnosis with us

We can often recognize the acute form of pilonidal sinus at a glance from its typical appearance. The symptoms that you describe in a conversation about your medical history (anamnesis) help us to classify your case. A predominantly sedentary job also gives us clues.

During a physical examination, we palpate the affected region around the gluteal fold and the coccyx. This makes it possible to recognize whether the skin is swollen and overheated or sensitive to pain and pressure. We can also see whether fluid mixed with pus or blood flows out of an opening when careful pressure is applied.

A blood test reveals changes that indicate inflammation: Elevated white blood cells, elevated C-reactive protein (CRP, a general inflammatory marker) and an increased erythrocyte sedimentation rate.

These examinations are usually sufficient for the diagnosis of pilonidal sinus. We rarely probe the fistula with a special, blunt instrument (button probe) due to the pain involved. Imaging procedures such as ultrasound, computer tomography or magnetic resonance imaging are usually not necessary.

Pilonidal sinus: prevention, early detection, prognosis

You cannot really prevent a pilonidal sinus. Nevertheless, some risk factors are known to favor pilonidal sinus. And here you can do something yourself to reduce the risk. Some tips:

• Avoid sitting for long periods at work and in everyday life: stand up more often and walk a few steps in between. Some work can also be done standing up. In general, it is advisable to integrate as much exercise as possible into your everyday life.
• Lose excess weight: Try to lose a few kilos if you are overweight or obese. Your entire body benefits from a healthier body weight. The best recipes for losing weight are a healthy diet, plenty of exercise in everyday life and sport. Of course, it is best not to become overweight in the first place.
• Pay attention to good personal hygiene, including in the anal region and buttock crease. This is especially true if you sweat a lot.
• Wear loose, breathable clothing to prevent sweat from building up.
• If there is a lot of hair in the coccyx area, regular shaving helps to remove the hair. Waxing or laser hair removal could also be alternatives.

There are no special measures for the early detection of coccyx fistula. Doctors often find the disease by chance during another examination when it is not causing any symptoms.

Course and prognosis for pilonidal sinus

The course and prognosis of a pilonidal sinus can vary greatly from person to person. Sometimes the disease progresses without symptoms and treatment is not necessary in this case. However, it can develop into an acute or chronic coccyx fistula at any time.

In the acute and chronic form of pilonidal sinus, however, surgery is unavoidable. And this is generally associated with some risks and can lead to complications:

• Pain after the procedure
• Infection of the surgical wound
• Limited mobility
• Impairments in everyday life when sitting or lying down

Depending on the surgical technique, it usually takes a few weeks or even months for the wound to heal after the operation. And sometimes the pilonidal sinus returns after the surgical procedure.

Pilonidal sinus: treatment usually by surgery

The treatment always depends on the shape of the pilonidal sinus. Those who do not experience any symptoms (asymptomatic form) do not require treatment. However, it can also develop into acute or chronic pilonidal sinus, which causes very unpleasant symptoms. To prevent this, you should pay particular attention to personal hygiene. If you have more body hair, it is better to remove the hair in this area – preferably permanently. This prevents broken hairs from growing into the skin right from the start.