What is pilonidal sinus disease (PNS)?
A pilonidal sinus (PNS) is a small hole or tunnel in the skin. It may fill with fluid or pus, causing the formation of a cyst or abscess. It occurs in the cleft at the top of the buttocks. A pilonidal cyst usually contains hair, dirt, and debris. It can cause severe pain and can often become infected. If it becomes infected, it may ooze pus and blood and have a foul odor.
A PNS is a condition that mostly affects men and is also common in young adults. It’s also more common in people who sit a lot, like cab drivers.
What are the causes of pilonidal sinus disease?
The exact cause of this condition isn’t known, but its cause is believed to be a combination of changing hormones (because it occurs after puberty), hair growth, and friction from clothes or from spending a long time sitting.
Activities that cause friction, like sitting, can force the hair growing in the area to burrow back under the skin. The body considers this hair foreign and launches an immune response against it, similar to how it would react when dealing with a splinter. This immune response forms the cyst around your hair. Sometimes a person may have multiple sinuses that connect under the skin.
Identifying a pilonidal sinus and recognizing signs of infection
You may not have any noticeable symptoms at first other than a small, dimple-like depression on the surface of your skin. However, once the depression becomes infected, it will quickly develop into a cyst (a closed sac filled with fluid) or an abscess (a swollen and inflamed tissue where pus collects).
Diagnosis is typically confirmed by a physician examining the buttock area.
Treatment depends on the disease pattern. The primary treatment for an acute 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 under local anesthesia.
Complex or recurring infections must be treated surgically, either through excision or unroofing the sinuses. Unroofing the sinuses, as shown in Figure 2, involves opening up the abscess and tracts and trimming the edges of skin.
Larger, open operations often result in better outcomes, although healing takes longer. Closure with flaps 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.
When the wound is closed, it must be kept clean and dry 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.
The signs of an infection include
pain when sitting or standing
swelling of the cyst
reddened, sore skin around the area
pus or blood draining from the abscess, causing a foul odor
hair protruding from the lesion
formation of more than one sinus tract, or holes in the skin
You may also experience a low-grade fever, but this is much less common.
How are pilonidal sinuses treated?
If your case is diagnosed early on, you aren’t experiencing severe pain, and there’s no sign of inflammation, it’s likely that your doctor will prescribe a broad-spectrum antibiotic. A broad-spectrum antibiotic is an antibiotic that treats a wide range of bacteria. It’s important to realize that this won’t heal the sinus tract, but it will give you relief from the infection and discomfort. Your doctor will recommend that you get a follow-up exam, regularly remove hair or shave the site, and pay particular attention to hygiene.
This procedure alleviates symptoms from an abscess, or a collection of pus inside the sinus. Before this procedure, your doctor will give you a local anesthetic. They will then use a scalpel to open the abscess. They will clean away any hair, blood, and pus from inside the abscess.
Your doctor will pack the wound with sterile dressing and allow it to heal from the inside out. The wound usually heals within four weeks, and many people don’t require any further treatment.
For this type of treatment, your doctor will first give you a local anesthetic. They will then inject phenol, a chemical compound used as an antiseptic, into the cyst. This procedure may need to be repeated several times. Eventually, this treatment will cause the lesion to harden and close.
This treatment has a very high recurrence rate. Therefore, it’s uncommon in the United States. Doctors turn to surgery as the treatment of choice in some cases.
If you have a recurring PNS or if you have more than one sinus tract, your doctor will recommend a surgical procedure.
You will first be given a local anesthetic. Then, the surgeon will open the lesions, removing all of the pus and debris. Once this process is complete, the surgeon will stitch the wounds closed.
After surgery, your doctor will explain how to change the dressings and will recommend shaving the site to prevent hair from growing into the wound.
What is the outlook for pilonidal sinus disease?
Depending on the severity of the disorder and the type of treatment, a PNS will usually clear up within 4 to 10 weeks.
What complications are associated with pilonidal sinus disease?
There are a number of complications that may arise from PNS. These include wound infection and a recurrence of the PNS even after surgery.
Signs that the wound is infected include:
inflamed, swollen skin
a temperature of 100.4°F or higher
blood and pus seeping from the wound site
a foul odor coming from the wound
How can I prevent pilonidal sinus disease?
You can prevent recurrence of PNS by washing the area on a daily basis with a mild soap, making sure all soap is removed, keeping the area completely dry, and avoiding sitting for long periods.