Pilonidal sinuses are little passages that appear in the skin between the buttocks and what is known as the natal cleft. These blind ending passages, which are called a sinus, can become infected and produce chronic infection, or acute infection within them.
Acute infection usually presents as an abscess, which often requires emergency treatment or even a brief admission under the surgical team. Chronic sepsis are the followers of acute abscess, where the patient's symptoms do not heal up or these sinuses can become infected in a more low grade manner and produce ongoing pain and discharge.
Pilonidal sinuses have been known to develop on the belly button or between fingers. In many cases, there is more than one channel. It can be asymptomatic with many patients experiencing no symptoms at all unless it becomes infected. If the sinus becomes infected, an abscess will likely develop, which is a painful collection of pus that causes symptoms including pain, a tender lump under the skin, redness of the skin, unpleasant smelling pus draining from the sinus, blood coming from the sinus, and a high temperature. These symptoms can develop quickly and over several few days.
It is not known what exactly causes pilonidal sinus and much more research is required, but they are generally thought to be caused by loose hairs pushing into the skin. A possible cause is deep layers of skin being stretched and moved. This leads to a hair follicle rupturing, which are the small holes that hair grows out of. Pressure and friction damage a hair follicle which causes a pilonidal sinus. If it becomes blocked, it can become enlarged and eventually burst, and a broken hair may push into the skin and become infected.
Environmental factors may also have a part to play. These can include wearing restrictive clothing, such as army uniforms, repetitive motion, such as bouncing around in the seat of a car, and poor personal hygiene.
On the whole it is young adults between the ages of 15 and 40 who are the classic group at most risk of developing this condition and as one gets older it seems to disappear with time. There are several other risk factors including obesity, having an above-average amount of body hair, which partly explains why more men are affected than women, having coarse and curly body hair, a previous injury to the affected area of skin, having a deep cleft between the buttocks, and having a job involving a lot of driving or sitting down for long periods. If the patient has a family history of the condition, this reduces their risk as more than one-third of people have a family member with the condition.
The patient will usually be diagnosed through a physical examination by their doctor. If infection is severe, blood tests may be performed for diagnosis. There is usually no need for imaging tests in cases of pilonidal cysts. However, patients will notice a pilonidal cyst before they are diagnosed. It is noticeable and easy to identify as it looks like a lump, swelling, or abscess at the cleft of the buttock with tenderness, and possibly a draining or bleeding area (sinus).
If there is no infection, there may be no need for the patient to have any treatment, and they will simply need to control the sepsis. They will have to keep the area as clean and dry as possible, and remove any hair, usually by shaving or using hair removal creams, which will reduce the risk of an infection. If it's an acute abscess draining it will perhaps remove the problem and it will heal up afterwards. But if it does not heal, it becomes infected, or there are chronic ongoing symptoms, then surgery is likely to be recommended.
There are many surgical operations that have been used for this condition. They all usually involve either a wide excision of the sinuses or excision and primary closure. The former involves the surgeon cutting out the section of skin containing the sinus, after which the wound is left open and packed with a dressing. During an excision and primary closure, the surgeon cuts out the section of affected skin before closing and sealing the wound with stitches.
Another treatment option for some pilonidal sinuses is scraping away ingrown hairs and from the sinus before sealing the area with an absorbable glue called fibrin glue. This can be done under general or local anaesthetic.
The advantage of having a wide excision is that the chances of an infection returning are low. But the patient will need to be prepared that the wound will take a long time to heal and dressings will need to be changed daily for two or three months. The advantage of the excision and primary closure technique is that the wound heals quickly. However, the chances of the infection returning are higher than with a wide excision. The advantages of the fibre glue treatment option are the patient will not require any dressings, there is relatively little pain, and the patient will make a quick recovery, likely able to return to their normal activities within one week.
These surgical techniques are relatively low risk. The aim of the treatment is to remove the sinuses and prevent ongoing chronic infection. However, the success rate of all these operations is limited to about 75%, and so around 25% of patients will get a recurrence afterwards, either immediately or in the more medium term. In rare cases, several complications can occur as a result of surgery, which include a recurrent pilonidal sinus or infection at the site of the wound during or after surgery.
There is no particular preparation needed for these surgeries, other than for the patient to be generally fit in order to undergo an anaesthetic. Patients will of course also need to remove all hair near the site of the abscess, a process known as depilation.
The patient may feel some discomfort following the operation, and will be given pain relief if necessary. Patients will usually be discharged on the day of the operation. Time off from work is likely required, but this does depend on how the patients feels and the type of work they do. Generally, patients are advised to avoid strenuous work for up to two weeks.
Whether a patient has any treatment, self-care is the most important part to managing the condition and preventing further complications from occurring. Patients should have a shower or bath at least once a day whilst the wound is being left open and packed with a dressing.
If there wound is closed with stitches, they will be advised to avoid having baths, at least for the first few days following surgery.
Patients should also avoid using soap when washing the wound so as to avoid irritation to the skin. When drying, the area following washing, patients should either use a soft towel or hair dryer. Wearing comfortable, loose, cotton underwear is advised. And finally, consumption of high-fibre foods to help soften the stools and reduce any straining is also encouraged.