We all know a person whose boasted about the length of time they've abstained from showering or bathing.
It's either an odd point of pride or a self-deprecating knock on their personal hygiene.
Either way, if they kept it up — say, for an entire year — they'd smell awful, would run the risk of infection and could be covered in acne and bumps.
Keeping it au naturel for that long is, besides a slow way to alienate yourself, not recommended, advises Dr. Cameron Rokhsar, an associate clinical professor of dermatology at Mt. Sinai Medical Center in New York.
Here's what would happen:
Unsurprisingly, a person would develop quite a funk after 365 showerless days.
Rokhsar said your stench likely would come as a result of the bacteria and dead skin accumulating on you.
After a year, he said, you'd have a build-up of skin stratum corneum, or dead skin on top of your skin. It includes a build-up of a protein our skin produces that has a funky odor to it. Bacteria also would accumulate on the skin, giving off a nasty smell when it mixes with our sweat.
Brown clumps would grow on you
Initially, said dermatologist Dr. Lauren Ploch, the skin would become oily or dry and become infected with fungus or yeast and then bacteria. The dirt on the skin could then cause warty growths.
Dr. Caroyln Jacob, director of Chicago Cosmetic Surgery and Dermatology, said the oily parts of your body would collect dirt and pollutants. This would happen most in places where your body produces the most oils, such as your underarms, behind the ears, on the neck and under a woman's breasts.
The body's dead skin normally rises to the surface and is flaked off through normal washing, said Jacob, a fellow of the American Academy of Dermatology. When that stops, the dead skin clumps together with your body's oils. The clumps would grow in patches and take on a brown hue once they collect dirt and other pollutants.
You'd be at higher risk for infection
We're taught early the first step to take when you get a cut is to wash it.
If you haven't washed in 365 days and you suffer an abrasion, the building bacteria on your skin means you may be more likely to suffer a soft tissue infection, notes Rokhsar.
"While infection may not be a concern in the beginning, carrying a large load of bacteria on the skin can pose a problem if the skin barrier were to become compromised in some way. i.e. through a cut or scrape," said Ploch, a member of the AAD.
Your head would itch
Dead skin would build on the scalp. We commonly call this dandruff, which causes your head to itch. But after a year, explains Rokhsar, your head would become "extremely itchy."
If not groomed, Jacob said hair becomes heavy with oil secreted from the scalp and the collected dirt and pollutants that stick to it. It would later, Rokhsar said, look matted and knotty.
You could break out in acne or puss bumps
As bacteria builds on your skin, said Jacob, it risks inflaming hair follicles, causing pimples. Rokhsar adds something called sebum would build up on your face, causing acne or puss bumps.
Your groin area will become a big problem
Jacob warns people to watch out for the groin area. She said you're likely to get rashes or something called intertrigo, a yeast and inflammation combination that goes from itchy and red to burning and painful.
Scum between your toes
Speaking of the groin, the fungus that will grow between your toes could easily spread to the pelvic area.
Jacob said dead skin would build up between your toes and become crusty. It could then harbor fungus, which could be transferred to your groin while putting your feet through your pants or underwear.
It could take weeks to return to normal
Turning yourself around could take time.
Rokhsar predicts it would take about a week to get back on track. However, Ploch hints it could take longer.
Some of her patients have gone months without washing a certain part of their body. It can take weeks, she said, for the skin to return to its normal state.
P.S. - Not everyone needs to shower every day
Dr. Elaine Larson, the associate dean for research at the Columbia School or Nursing and School of Public Health, said "frankly" showering and bathing is mostly for "aesthetics."
Showering every day, she said, is unnecessary. Every two, three or even four days is acceptable as long as you don't stink up the place. She said, generally, the organisms naturally found on her skin protect us from picking up harmful germs.
The exception, she said, are people with fragile immune systems, such as newborns, the elderly and people suffering from cancer.
Follow Sean Rossman on Twitter: @SeanRossman