Pilonidal Sinus

A pilonidal sinus is a minute hole or opening which may also resemble a tube-like structure present in the skin. Sometimes, these openings may be filled with pus or other fluid, forming an abscess or cyst. These occur at the crevice on the upper portion of the hips. Pilonidal cysts often contain dirt, hair, or debris. When infected, it may lead to severe excruciating pain. Once it is infected, pus or blood can be seen oozing out from the site. PNS is a disorder that primarily affects men but is also prevalent among young people. It's also more frequent among people who spend a lot of time sitting, such as cab drivers.

Pilonidal Sinus Causes

Although the exact reason for the disease is unknown, certain factors are found related to the occurrence of this condition. These factors include:

  • Hormonal changes as seen in puberty 
  • Obesity 
  • Hair growth
  • Experience of trauma or irritation
  • Friction caused by clothing or sitting for an extended period

When you sit or perform other activities that cause friction, the hair developing in the region can burrow back under the skin. In response to this hair, the body mounts an immune response similar to what it would do to a splinter. When this response occurs, your body produces the cyst surrounding the hair. Many people can have more than one sinus under the skin.

Signs or Symptoms of Pilonidal Sinus

The natal cleft, which is the apex of the buttocks crease, right beneath the tailbone, is affected by a pilonidal sinus. Depending on the severity of the illness, symptoms might range from moderate to severe. The common signs and symptoms observed are as follows:

  • Tiny depression in the skin 
  • Discomfort
  • Irritation
  • Growth of a painful mass or abscess. The fluid may also contain blood or maybe clear.
  • Tenderness and redness in the area
  • Bad or foul smell 
  • Fever 
  • Nausea 

Possible Treatment 

The pilonidal sinus treatment plan is based on the type and stage of pilonidal sinus. These are as follows

  • No symptoms: When you don't show any symptoms of the disease, your physician may advise you to clear any hair if present there. Also, he will advise you to maintain excellent personal hygiene and keep the area as clean as possible.
  • Acute-onset condition: When there is a rapid onset of the condition, you may experience pain and pus draining from the area. You will be prescribed pain medication such as Ibuprofen or paracetamol. If needed, a small surgery will be done to drain the pus.
  • Chronic or long-standing condition with symptoms: In such cases, mostly surgery is planned. Your physician will discuss all the advantages and complications of the surgery. The surgery will involve an incision at the site of the sinus along with the removal of the infected sinus and the adjacent tissue. This is then left for healing. Depending on your condition, the doctor may decide to leave the wound open or will give a suture for healing. At times, a flap procedure may be required.

Alternate Name 

Pilonidal abscess; Pilonidal disease; Pilonidal cyst.

Differential Diagnosis of Pilonidal Sinus

Sacral osteomyelitis can be misinterpreted as a pilonidal sinus because the sacrum is close to the rectum. Both these conditions have some symptoms in common, such as pain, reddening, and swelling. Other conditions which might be confused with a pilonidal sinus are: 

  • Abscess
  • Hidradenitis suppurativa
  • Inflammatory bowel diseases
  • Anal fistula

Primary prevention 

The following steps can be taken to avoid a pilonidal sinus.

  • Washing and drying your buttocks regularly
  • To reduce your risk, you should lose excess weight 
  • To keep pressure off the region, avoid sitting for too long 
  • The hair surrounding your buttocks should be shaved


26 per 100,000 people. Pilonidal illness is more common in men, with a 3-4:1 male-to-female ratio. It affects mostly Caucasian individuals in their late teens to early twenties, with a decrease after age 25 and a rarity after age 45.

Expected Prognosis

Overall, the prognosis for pilonidal sinus is very good and it hardly causes long-term injury. After treatment, a pilonidal sinus might reappear, but keeping excellent cleanliness practices and eliminating hair from the region will help lessen the chances.


The most commonly recognized notion about pilonidal sinus illness is that it begins with an infected or inflamed hair follicle in the crevice area above your buttocks. This inflammation blocks the follicle's entrance, causing it to stretch inwards, leaving a pit or a hole. This may later develop like a tube to form a sinus-like structure. 

Possible Complications

A pilonidal sinus can lead to a variety of problems when left untreated or when the condition recurs even after the surgery has been done. These complications include:

  • Intense pain 
  • Swelling and inflammation in the skin 
  • Low-grade fever
  • Pus drainage from the site of infection or surgery
  • The foul stench from the wound
  • Poor wound healing
  • Numbness in the wound
  • Bleeding 
  • Scarring 
  • Allergic reaction and blood clotting 
  • In the worst-case scenario, it may lead to osteomyelitis, and skin or bone cancer.

Our BLK-Max Medical Experts

If you are facing any similar signs or symptoms please contact the BLK-Max team to schedule an appointment at : +91-11-30403040

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