How You Got a Pilonidal
There is a basic set of factors that underlie a person’s susceptibility to Pilonidal Disease and this is certainly not an all-inclusive list; these are only KNOWN risk factors:
- Family history of Pilonidal Disease
- Fetal development problems Spina Bifida Occulta
- Shape, size and scaliness of the person’s hair (head and body)
- Amount of hair in the buttock cleft & buttocks
- Size of the pores in the skin over the tailbone
- High degree of friction and pressure on the tailbone (such as sitting improperly)
- Traumatic injury to the tailbone (such as a fall or impact from a kick)
- Participation in high tailbone-impact activities (such as horseback riding)
- Depth of the buttock cleft (impacted by weight and genetics)
- Shape of the buttock cleft (overhanging areas, dips)
- Tendency towards blocked hair follicles (acne, boils, sebaceous cysts)
- Tendency towards other skin problems (eczema, etc…)
- Weak immune system
- Suffers from Hidradenitis suppurativa
This organization has chosen to follow the philosophies of Dr. John Bascom who is largely considered the foremost expert in the world on the treatment of Pilonidal. Now passed on, Dr. Bascom performed over 600 Pilonidal surgeries throughout his career and his work is continued by his son, Dr. Thomas Bascom.
Understanding Follicular Occlusion
Follicular Occlusion is medical terminology for “blocked pores.” What that means is the stretched pores in the midline of the natal cleft (you probably refer to this as your butt crack) become blocked with debris. On most other body parts, such as the face, this process results in a common pimple. The natal cleft, however, is a special place where lack of oxygen allows anaerobic bacteria to frolic and thrive. But we will come back to bacteria in a moment because bacteria are just one ingredient of a Pilonidal stew.
Your Skin As a Protective Barrier
The most important thing to recognize is that your skin is the largest organ in your body. It is a protective wrapper that keeps bacteria and parasites from entering the body. The reason why Pilonidal Disease is really a dermatology issue is because the abscess forms when bacteria breach the protective, gate-keeping layer of skin in your natal cleft. How does that happen? Through stretched pores that have been blocked by gunk and eventually rupture.
How the Pores Got Stretched
When the body rises from a sitting position, gravity naturally exerts force pulling the tissues in the buttock midline down at the same time as the body is being propelled upward. The pull of gravity stretches the pores in the buttock midline – and so does another culprit: slouch sitting. Mother nature endowed us with “sit bones” at the junction of our legs and buttocks, but many of us are a little lazy when we sit and we slouch forward in our chairs (raise your hand if you are doing this RIGHT NOW!) So, there you are with some pores in your buttock midline that have become stretched out wider than they should be. They might look like this:
How They Got Full of gunk
Once the follicles have been stretched out, they provide a very convenient place for stuff to collect; such as dead skin cells, sweat, clothing lint, and hair. As the crud fills in the stretched pores, they become blocked and the oils (sebum) that are naturally secreted by those pores can no longer flow. The oil backs up inside the follicle and causes it to stretch even more. As the crud builds up, the follicle becomes inflamed and eventually ruptures. The rupture spills the contents of the follicle and an inflammatory response occurs. Here in Pilonidal world, we now call this a “pit”. Pits are bad.
How They Got Infected
The pit is the start of a Pilonidal abscess. With the natural barrier of skin breached, the anaerobic bacteria (we told you we would meet Mr. Bacteria again) that normally live in the body locations where there is no oxygen have an opening that allows them to go off exploring in the fatty tissues of your bum. They invite friends, throw wild parties, and reproduce with abandon causing a secondary bacterial infection. Infections caused by anaerobic bacteria are characterized by abscess formation, foul-smelling pus, and tissue destruction. For those of you reading this right now with an ache at the top of your buttock cleft, this should be starting to sound very familiar…
One thing that continues to raise questions are those people who develop a Pilonidal after a traumatic tailbone injury. The speculation from our team of Medical Advisers is that at the time of the injury there may have been a pimple or even a pit already formed in the buttock midline of the patient prior experiencing trauma to the tailbone area. Or the innate immune system of the body may have been managing minor ruptured follicles quite nicely on its own until the trauma occurred. The trauma disrupts the normal defenses in tissue, leaves the area swollen and breaks the tissue walls that normally isolate pimples/pits to prevent infection. With the defense system down, bacteria moves in and an abscess results.
(My personal experience as a person prone to Pilonidals is that this process of follicle stretching & blocking is a constant process that is ongoing and can be managed at the early stages if you know what to look for. I’ve had easily 8 instances since my surgery in 2000 where a pimple formed in the midline and I was able to treat it with No Bump to keep it from turning into a new abscess).
It Can Be a Hairy Subject, But Not Always
Even though Pilonidal technically means Nest of Hair, only 50% of abscesses have hair in them. It has been noted that because of the scales on a hair shaft, hair does travel into a pit or sinus when the base of the hair is pressed into the opening – as through normal friction of the buttocks. Surgeons looking at removed Pilonidals have found hairs from the heads of patients and hairs from patient’s bedmates snuggled into the Pilonidal abscess.
It Can Be a Family Affair
It is common for Pilonidal Disease to run in families and it has been suggested in medical literature that this is due to an inherited shape/depth of the natal cleft and inherited propensity towards skin problems due to blocked pores. Just one more genetic gift from Mom and Dad. Be sure to thank them!
Pilonidal Disease is linked with 3 other conditions in what is known as the Follicular Occlusion Tetrad (Acne Conglobata, Dissecting Cellulitis, Hidradenitis Supperativa, Pilonidal). All 4 diseases share a common pathophysiology (functional changes that occur due to a disease) that is unique to the group. We regularly find people who are actually suffering from Hidradenitis Supperativa that have been misdiagnosed as Pilonidal, but having both at the same time is also a possibility. A good rule of thumb is that if it’s in the butt crack, it’s Pilonidal. Anywhere else (thigh, groin, underarm, under breast or other soft body folds, etc..) it’s more than likely Hidradenitis.
It is not at all uncommon for babies to be born with a Sacral Dimple and it is important to note that this is not the same as a Pilonidal abscess as it is discussed on this site even though your pediatrician might refer to it (wrongly) as a Pilonidal Dimple. A condition known as Spina Bifida Occulta (spine failing to close fully during gestation) can leave a hole over the tailbone that resembles a Pilonidal sinus opening and there is often hair at the site of the defect, this occasionally develops into Pilonidal Disease later in life. Other problems during fetal development can leave a “hollow” area at the base of the spine, which can lead to Pilonidal Disease later in life. Many years ago it was believed that all Pilonidal Cysts were congenital – the majority of surgeons now believe that almost all cases are acquired. If you are seeing a doctor who is telling you that all Pilonidals are congenital, then it is highly recommended that you find another doctor who’s been keeping up with current treatments and research.
Now that you know what a Pilonidal is, you’re probably wondering if that’s what is causing your tailbone pain. Start here, then see a doctor to be sure.
In Fact Sheet format, the questions most often asked on our forums about diagnosing Pilonidal Disease so you can skim quickly to what you need.
Our gallery of photos ranges from pictures of flare-ups to healed scars post surgery. **There are graphic surgical pictures.
This page last updated: January 2, 2019