Pilonidal Sinus: Dermatologist Dr. Kasten on Causes, Diagnosis, and SiLaC Laser Therapy

Dr. med. Robert Kasten is a board-certified dermatologist and has been running his dermatology practice in Mainz since 2006. As an experienced skin specialist, he performs a wide range of dermatological procedures. For many years, his treatment portfolio has also included SiLaC laser therapy by biolitec, used for the treatment of pilonidal sinus.

Dr. Kasten, what exactly is a pilonidal sinus and how does it develop?

A pilonidal sinus is a chronic inflammatory condition located in the natal cleft. It is caused by ingrown hairs that trigger a foreign body reaction. This leads to the formation of cavities beneath the skin, which may produce a foul-smelling discharge.

Strictly speaking, the term “coccygeal fistula” is not entirely accurate, as the inflammation typically develops over the sacrum rather than the coccyx, and the fistula tracts are not connected to the bone. The more appropriate terms are pilonidal sinus or sinus pilonidalis. These names reflect the origin of the condition—pilus (Latin for hair) and nidus (nest).

Are there specific risk factors that promote this condition?

Yes. The condition primarily affects younger men, especially those with increased body hair and a tendency to sweat more. Prolonged sitting can also contribute to the development of a pilonidal sinus.

What symptoms might indicate that I have a pilonidal sinus?

Many patients first notice moisture in the gluteal cleft, often visible as stains in their underwear. Some also report an unpleasant odor. In more advanced cases, painful inflammation, swelling, and abscess formation can occur.

How do you diagnose a pilonidal sinus? Are there specific diagnostic methods?

In most cases, the diagnosis can be made clinically. Using a dermatoscope, we can identify so-called “pits,” which are the small openings of the fistula tracts on the skin surface.

Sometimes, granulation tissue (“proud flesh”) forms around these pits, appearing as reddish, moist, raised tissue. In selected cases, imaging techniques such as ultrasound or MRI may be necessary. These examinations are painless.

During treatment, the extent of the fistula tracts is assessed using a probe, usually under local anesthesia.

Does a pilonidal sinus always require treatment, or can it heal on its own?

A pilonidal sinus rarely heals spontaneously. This is because the tracts and cavities are lined with epithelial tissue, which prevents closure, and hair remains trapped beneath the skin.

For healing to occur, both the hair and the epithelial lining must be removed. In addition, permanent hair removal using laser or IPL is recommended to reduce the risk of recurrence.

If a chronically inflamed pilonidal sinus persists for many years, there is a rare risk of developing a squamous cell carcinoma.

What treatment options are available?

Self-treatment is not effective. However, a specialized physician can provide relief from this often distressing condition.

Today, minimally invasive treatment options are available, allowing for a quick return to daily life. These include:

• Pit-picking, where the fistula openings are removed
• Laser ablation, where the epithelial lining of the fistula tracts and cavities is destroyed

How does SiLaC laser therapy work, and what are its advantages?

During laser treatment, the fistula tracts are ablated so that the channels and cavities can close. Beforehand, the tract system is thoroughly cleaned of hair and inflamed tissue.

Healthy skin and surrounding tissue are preserved, enabling patients to resume normal activities quickly. The procedure can be repeated if necessary.

Additionally, long-term hair removal with laser or IPL is essential to prevent recurrence.

How long does the treatment take, and what is the recovery time?

The procedure typically takes between 30 and 45 minutes and is performed under local anesthesia.

The time to return to normal activities depends on the severity of the condition and the extent of treatment. Most patients can shower again the day after the procedure. However, swimming, sports, and sauna should be avoided for approximately two weeks.

Complete wound healing may take several weeks. If discharge persists after six weeks, an additional laser treatment may be required.