What is it?

A pilonidal cyst is an abscess which usually contains hair within the cleft of the buttocks at the base of the tail bone. They can be espescially painful and oozey or completely asymptomatic. Some discover the problem at the emergency room, complaining of terrible pain and a rear end they cannot sit or lay upon. Some people will notice a bump or a hole and never think another thought about it, experiencing no pain.

The origins on the cyst within the body are debated. Some people are born with a pilonidal dimple (such as myself), which is a small open indentation (think buttcrack mini-belly button), however they have no more prevalence towards having pilonidal cysts than anyone else. Some think it is a congenital condition. Most doctors currently agree that enlarged hair folicles allow easier penetration from debris in the area.

Since most of these cysts contain hair, it is considered to be the culprit. In that region hair can grow up and out, only to find opposition from the opposing butt cheek. Having nowhere to grow, it curls back down and becomes infected. Hair from other parts of the body can drift into the crevasse, where the comparatively glacial cheeks push them into the follicles. Unfortunately for those who don't fit the description, having these cysts chronically has been called hirsute man's disease, though it is more formally called pilonidal disease.
I'm not hairy. Really. I'm not a man either.
These cysts, as a chronic disease, were first recognized in World War II, and was called jeep rider's disease (80,000 cases1). Even today, two things are commonly mentioned to doctors during an initial visit: recent trauma or bump to the area or having been seated for long periods of time, such as a car ride.
As a sufferer I must say that the name jeep riders's disease seems quite apt. I cannot think of anything more intolerable to a rear suffering the turmoil of a pilonidal cyst than a bumpy ride in a government jeep. It feels like your tail bone is grinding its way through the skin. There isn't a comfortable position. The best you can do is keep the weight off your tail bone. That is impossible in a bumpy crap-ass jeep in war terrain (I assume). The name states ideally the worst-case-scenario.

The cyst experience

The cysts can be big (like a golf ball or bigger) or small (like a pea) but size has little to do with the amount of pain which may be present. They can burst, leaking a sticky, smelly, and itchy goo and blood. If they do pop, they are almost certainly infected. Although this usually serves to relieve much of the pain, it isn't a good idea to let them get to this point. Most doctors treat the first ocurrence of a pilonidal cyst by lancing and draining it, packing it with gauze (to be removed in a few days), and prescribing an antibiotic.
I let mine get bad. I discovered a hole where there shouldn't be a hole. I freaked out. Since it had popped, the doctor gave me antibiotics. Since I mentioned having on-going butt pain which I'd attributed to weight loss, he referred me to a surgeon to have the cyst "cored".

When I saw the surgeon, he wanted to lance it to get more gunk out and relieve the pressure, and schedule surgery in a few weeks. The lancing wasn't too bad since he shot me with a local anesthetic. It wasn't pleasant, but it was okay enough that I felt I could deal with a few more lance-and-drains should it recur. I put off surgery (I was a chicken).

The Recurring-Cyst Experience

Even one who only experiences a single painful cyst will be sympathetic to the conditions described by the disease. One cyst is agonizing aplenty. Continual recurrences are a nightmare.

If there is no recurrence count yourself very lucky, many people will have another cyst. Surgery is generally considered the treatment. Doctors talk about it in a nonchalant manner, and to them it is perhaps not an everyday operation, but it isn't a difficult or overly dangerous one. Being a lay-person and writing this from the patient point-of-view, it sounds atrocious and horrible (particularly hearing terms such as "coring" and "saucerization").
If you're of the view that life isn't fair, have heart. Rush Limbaugh suffered has suffered pilonidal torture. In fact, it got him a deferment from the draft2.

For me, it did recur. It opened up about two weeks after the first lancing, but I ignored it since it felt better after popping. Just last week, after a weekend backache and the familiar sit-down pain, I knew it was back, and bad. I wound up in the emergency room, crying and begging for painkillers. It was lanced again (this time FAR more painful than the first). My doctor told me to stop being a wuss and schedule the surgery.

Treatment

There are several techniques but they all sound fairly similar except in how they are closed. The surgeon will go in and remove the cyst, such that normal tissue should fill in. The hole with either be: left open to be packed twice daily with gauze, sewed shut, or (in extreme cases) a skin graft may be used to flatten the cleft. Left open, there is less liklihood of recurrence, but it can take up to 2 months before it will fully heal and will require daily care for at least that long. These surgeries generally won't require a stay in the hospital, and you will want to take rest for about a week.
I'll update this after I have my chance under the knife. I am anxious to rid myself of this menace, though understandably concerned about the procedure.

It's taken me a while to get around to writing this. You see, who wants to stand up and talk about the extra holes in their butt, and what lies beneath? What woman wants to admit to having a hirsute, jeep ridin' man's disease?


Update (as promised!)

Before the surgery, I prepped by having my sister write "Hi Dr. Kravitz! :)" on my right buttcheek. I was taken into the pre-op area and prepared. They inserted my IV, and I was told that due to a kiwi allergy, they would be using latex free everything, due to a connection between kiwi allergies and latex allergies. I was wheeled into the operating room and was introduced to everyone. I was told to lay on my stomach, and they got me into the right position (ass end WAY up). The anesthetist began pushing the drugs into the IV, and I began to get giggly. Then Dr. Kravitz found the drawing on my bun. That's the last I remember until I was being wheeled into the post-op area.

I was still under the effects of general and a strong local anesthesia. The nurses asked how I was and laughed when I said "I feel quite lovely, thank you."

I was released fairly quickly, and didn't experience any pain whatsoever until I awoke the next morning and found the local (ie, ass) anesthesia had worn off. Then I spent an awful week trying to figure out the best way to be comfortable (there isn't one).

I've had no problems of recurrence, everything is all closed and now my ass is normal, with no extra holes or anything unusual (except the resulting scar). There has, however, been quite a bit of continued discomfort with sitting; it still feels as though I have a cyst which will pop any moment. I have been assured, however, that this is just the scar tissue, and that it will go away with time. So far, this has been a success and I recommend it to any pilonidal cyst sufferer.

Cyst Prevention

With or without surgery, prevention is key. If the patient is hairy in the area, shaving may be a good (if awkward) idea. The area must be washed daily. Many self-care websites recommend using an anti-ingrown hair solution. Sitting for long periods is a really good way to bring on a painful rear-end. Travel may make staying seated unavoidable at times, but don't exacerbate the problem in front of a computer or television.
sources: I wrote this from memory, having read a lot on the internet and visited my doctors very regularly regarding this very topic. I quoted the first article below twice, but edited out one reference to a now-debunked theory about the sinus being present at birth as a vestigial (insert medical gobbledeegook here). The phrase they used made me think "vestigial tail", which gave me a giggle, but really bore no real relevance. The 80,000 cases in WW2 just seemed like a neat stat to quote. So I attribute the article below. Any errors or omissions are because I'm not a doctor, just a person trying to learn about an unpleasant and painful but rather benign condition.
  1. http://www.emedicine.com/emerg/topic771.htm
  2. Thanks to BJuarez pointing this out to me, and http://past.thenation.com/issue/000619/0619franken.shtml for backing it up.