A pilonidal cyst develops in the cleft between the buttocks — the intergluteal cleft. Just as any other cyst, a pilonidal cyst can become infected and pus-filled.
If an infection does happen, the cyst turns into a pilonidal abscess, and this is when it can be painful.
A pilonidal cyst resembles a large pimple and is more common in men than in women. It is also found more often in younger people than in older people. Those who are obese, have a sedentary lifestyle, significant body hair, or an injury or irritation in the area, are at greater risk of having one.
If a cyst does become a problem, a doctor can either drain it or use surgery to remove it.
Pilonidal cyst symptoms can include:
- pain accompanied by redness and swelling
- pus or blood oozing from the cyst
- a nasty odor from the pus
- pain when touched
- a fever
Pilonidal cysts vary in size and can be anything from the size of a small pimple to covering a much larger area.
At present, the exact reason why pilonidal cysts develop is unclear.
Ingrown hairs are thought to be one cause. Indeed, the name "pilonidal" means "nest of hair." Doctors can sometimes find hair follicles tucked inside the cyst.
Another possible cause is that a pilonidal cyst is the result of force or friction applied to the area.
A pilonidal cyst could also be caused by repeated local injury. During World War II, more than 80,000 American soldiers were hospitalized with the condition. This led to it being known as "Jeep rider's disease."
A pilonidal cyst is also more likely to develop in people who were born with a small dimple between the buttock cheeks, which can become infected.
Diagnosis of a pilonidal cyst can be made by a doctor through a physical exam and by asking questions of the person. These questions may include the following:
- When were the symptoms first experienced?
- Has this problem happened before?
- Has there been a fever?
- What medications are taken regularly?
Antibiotics do not seem to be helpful in healing a pilonidal cyst. There are many other treatment options, however.
Incision and drainage
If it is someone's first pilonidal cyst, the preferred treatment method is incision and drainage. In this procedure, a doctor cuts into the cyst and drains it.
The hair is removed, including any hair follicles, and the wound is left open, and the space left behind is packed with gauze.
A key benefit of this procedure is that it is simple and straightforward, and it is done using local anesthesia.
A downside is that the gauze has to be changed regularly while the cyst heals, and this can take up to 3 weeks.
This procedure starts in a similar way, with a doctor cutting and draining the cyst, and removing pus and any hair from inside. Instead of leaving the wound wide open, however, they sew the edges of the cut to the bottom of the cyst, forming a small pouch.
While this is surgery, it is done as an outpatient procedure, using local anesthesia. This means the doctor can make a smaller, shallower cut so that the pouch is not packed with gauze. There is no need to replace the gauze daily, either.
On the other hand, this procedure takes longer to heal, about 6 weeks, in fact. A doctor specially-trained in the technique is also needed to carry it out.
Incision, drainage, closing of wound
In this procedure, a doctor drains the cyst but does not leave the wound open.
Again, there is no need to repack any gauze, as the doctor closes the wound at the end of the surgery.
The main disadvantage with this surgery is that problems are more likely. One such problem is that it is harder to remove the whole cyst.
Again, this procedure is usually carried out by a specially-trained surgeon in an operating room and involves general anesthesia.
As with any form of surgery, whether outpatient or inpatient, it is important to take note of all instructions relating to the at-home care, especially if gauze needs removing and repacking.
General advice for recovery includes:
- Keeping the area clean.
- Checking for signs of an infection. This could be an area of redness, pus, or pain.
- Making sure that all follow-up appointments after surgery are kept, so the doctor can see how the cyst is healing.
- A doctor may also ask a person to remove hair from the area.
A pilonidal cyst may also have complications, which may include the following:
- development of an abscess
- recurrence of the cyst
- a systemic infection that spreads through the body
Very occasionally, a form of skin cancer can develop in the cyst.
Generally, the outlook for anyone with a pilonidal cyst is excellent, with a complete cure being possible.
It must be remembered, however, that a pilonidal cyst may recur in anyone who has had one removed surgically.
Such recurrence is common and is estimated to happen in up to 40-50 percent of individuals.
Maintaining good hygiene of the area at the base of the spine is important. This helps prevent the development of pilonidal disease, as well as its recurrence if it does occur.
Steps that people can take to reduce their risk of pilonidal cysts developing include:
- keeping the area clean and dry
- keeping the area free of hair, by shaving or using depilatory creams
- avoiding sitting for a long time
People who are overweight may also find that weight loss reduces the risk of cysts developing, as well as recurring.