Pilonidal Disease


Pilonidal disease is a chronic skin infection in the crease of the buttocks near the coccyx (tailbone). It affects about 70,000 people in the US annually and is more common in men than women. Most often it occurs between puberty and age 40. People who are overweight and who have thick, stiff body hair are more likely to develop pilonidal disease. 









 

 

Figure 1: Pilonidal disease affects the buttock crease area. Two small openings are shown (A).

CAUSES

The cause for pilonidal disease is not completely understood. Hair often grows in the cleft (crease) between the buttocks. These hairs can traumatize and penetrate the skin at the top of the buttock crease. Hairs can get caught under the skin in this area.  This can result in irritation, infection, and formation of an abscess. 

SYMPTOMS

Symptoms can vary from very mild to severe.  The symptoms may include:

  • Small dimple
  • Irritation
  • Large painful mass (inflammation or abscess)
  • Clear, cloudy or bloody fluid drainage from affected area
  • If infected, the area becomes red and tender and the drainage (pus) smells foul
  • If infected, may have fever, nausea or feel ill

DISEASE PATTERNS

Nearly all patients are initially diagnosed by having an acute abscess episode (the area is swollen, tender, and pus may drain from it). After the abscess goes away, either by itself or with medical care, many patients develop a pilonidal sinus. The sinus is a cavity below the skin surface that connects to the surface through one or more small openings (pits). Some sinus tracts may resolve on their own, however, most patients need minor surgery to remove them. 
 

DIAGNOSIS

Diagnosis is typically confirmed by a physician examining the buttock area.

TREATMENT

Treatment depends on the disease pattern. Once diagnosed and any active inflammation or infection is taken care of the primary therapy is keeping the area free of hair (topical depilatories, shaving, laser hair removal). The treatment for an abscess is drainage. An incision is made that allows pus to drain, reducing inflammation and pain. This procedure can usually be done in a physician’s office using local anesthetic. If there is significant inflammation of the skin antibiotics may be prescribed. Keeping hair out of the area (shaving, laser, etc.) can be utilized to help treat both active and chronic disease. 

SURGICAL TREATMENT

Complex or recurring infections are treated surgically, either through excision or unroofing (opening) the sinuses. Unroofing the sinuses, as shown in Figure 2, involves opening up the abscess and tracts and trimming the edges of skin.  

Figure 2: Drawing B shows inflammation located deep under the skin above the tailbone. The dashed line indicates the area to be opened or unroofed. The dashed line in drawing C shows the entire inflamed tissue that will be removed.

Operations with complete excision of tracts and any abscess cavity often result in better long-term outcomes, although healing takes longer. Closure with flaps (moving healthy body tissue into the area) has a greater risk of infection, but may be required in some patients. Your colon and rectal surgeon will discuss all the options and help you choose the most appropriate surgery. 

POSTSURGICAL PROGNOSIS

When the wound is closed, it must be kept clean, dry and free of hair until the skin is fully healed. If the wound is left open, dressings or packing are used to help remove secretions and allow the area to heal from the bottom up. 

After healing, the skin in the buttocks crease must be kept clean and free of hair. It is necessary to shave or use a hair removal agent every 2 or 3 weeks until the age of 30. After that age, hair shafts thin out and soften and the depth of the buttock cleft lessens. Pilonidal disease can be a chronic, recurring condition so it is important to follow your physician’s postsurgical care instructions. 

WHAT IS A COLON AND RECTAL SURGEON?

Colon and rectal surgeons are experts in the surgical and non-surgical treatment of diseases of the colon, rectum and anus. They have completed advanced surgical training in the treatment of these diseases as well as full general surgical training. Board-certified colon and rectal surgeons complete residencies in general surgery and colon and rectal surgery, and pass intensive examinations conducted by the American Board of Surgery and the American Board of Colon and Rectal Surgery. They are well-versed in the treatment of both benign and malignant diseases of the colon, rectum and anus and are able to perform routine screening examinations and surgically treat conditions if indicated to do so.

DISCLAIMER

The American Society of Colon and Rectal Surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention and management of disorders and diseases of the colon, rectum and anus. These brochures are inclusive but not prescriptive. Their purpose is to provide information on diseases and processes, rather than dictate a specific form of treatment. They are intended for the use of all practitioners, health care workers and patients who desire information about the management of the conditions addressed. It should be recognized that these brochures should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtain the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient. 

ASCRS members regularly review and update information for accuracy. We believe things are medically accurate at the time they were produced.