Fun with Fingernails

We paint them. Polish them. Trim and manicure them. Bite them. Run them down chalkboards. Our hands are intimate parts of our being and the nails are their crowning symbols. They broadcast our health, diseases, and personalities.

But what do you really know about your fingernails? When you were about a 9 week-old embryo, your skin started thickening on the ends of your fingers. But rather than forming a claw or hoof as it would in other animals, that thickened skin migrated to the backs of the fingers and set up shop as your fingernail. For the rest of your life these cells will produce the hard protein called keratin that gives nails their shield-like resilience. Even after death, the finger and toenails are some of the last tissues to degrade thanks to keratin.

Many medical students and funeral directors have noticed that their cadavers have longer nails.  This has led to the widespread belief that our nails continue to grow after we expire. While there is no evidence against this, it is much more likely that the surrounding tissue simply shrinks and creates the appearance of a longer nail.  The novel All Quiet on the Western Front, seems to be credited for this urban myth as the 19 year old main character ponders death. But I think its impractical to believe the notion didn’t exist prior. Perhaps a few cells do divide in an immeasurable length after death; but ultimately, who really cares?

Your probably have noticed your fingernails grow faster than your toenails. But did you notice the middle finger nail (your “driving finger”) grows fastest and the poor little pinky is the most sluggish? Also your nails grow a little faster on your dominant hand. It’s generally accepted that finger nails grow three millimeters a month and toenails a glacially slow one millimeter.  So it may take a full year for a toenail to regain it’s normal shiny appearance after dropping something on it. One great way to quickly grow beautiful nails is to become pregnant. But 18 years of biting them in anxiety unfortunately follows.

A doctor can tell a lot about your health from your nails and nail beds. Conditions like lupus, psoriasis, liver failure, iron deficiency, thyroid problems, and even arsenic poisoning all have very characteristic appearances. The nails also offer visual clues to a wide range of genetic conditions that may have no other skin manifestations at all. Taking a toxicology sample of a nail can help forensic teams establish evidence in suspected poisoning cases. Scraping underneath the nails can yield an attacker’s DNA if the victim managed to claw off a little skin before their demise. The Salem Witch Trials of the late 1600’s also teach us that driving wooden pegs underneath a suspected witch’s fingernails will elicit a confession of sorcery.   

Melanoma of the nails is a particularly frightening entity. I would encourage women who paint their nails to periodically let their doctor inspect them in their natural state. Dermatologists get a sinking feeling in their stomachs when a patient has a dark streak of pigment on their nails and cannot say how long it has been present. While nail streaks can be common in darker skinned races, in Caucasians it is melanoma until proven otherwise. Melanoma of the nail also carries a dismal survival rate unfortunately.  It took reggae legend Bob Marley’s life at the age of 36. He complained of a sore toenail for months before learning he had melanoma. So get any suspicious areas checked by your doctor—don’t simply paint over the problem.

And speaking of paint, the first modern nail polishes were actually exterior automobile paint. Cleopatra reportedly used henna to darken her nails and gold manicure sets have been excavated predating her reign in Egypt.  In the 17^th century, spotting a Chinese gentleman with long nails usually indicated he was wealthy enough to never have to perform manual labor. Elaborate bamboo and gold splints were used to protect the nails when lengths of five inches or more were reached. I recently saw a Discovery Channel show with a lady from Houston sporting twenty-two inch curly-Q nails. Needless to say, she was unable to work buttons on a telephone, cut her own food, or hold a job. I shudder to imagine how she tended to her bathroom necessities.  Selectively growing out the pinky nail is a common practice I observe in many patients. I used to believe that it was a sign of cocaine use (as it could be used as a dipper and easily snorted) but I think most people just like to scratch themselves with it.

As we age, the nails can become brittle, opaque, or thickened.  They generally grow slower. Ridges that run in a vertical fashion are a normal development in many people. This can be from a loss of natural oils and moisture levels in the nail plate. Rehydrating the nails twice daily with a good cuticle oil and Vitamin E can soften the ridged appearance. The thickening of the nails can managed with a good urea cream available without a prescription. However you’ll want your doctor to ensure you don’t have an infection if several months of application don’t resolve the problem.

Ingrown nails also start to become more common as we marinate through the decades. They can lead to infections. If your nails have significantly changed for the worse, it may be worth a trip to your doctor to ensure you do not have an infection, nutritional deficiency, or hormonal imbalance. The vast majority of nail cases I see are simply related to the aging process and are of no threat to anyone’s health.  Infections spread through nail salons are also always a possibility. Most places adhere to strict standards fortunately. I think nail salons are an easy target when people first come down with a nail infection. While they might be at fault, it's more likely you picked it up somewhere else given the hygiene rules they are required to follow. And it is not just fungus waiting to camp out on your nail. There are scores of molds, yeasts, bacteria and viruses all competing with your natural host organisms to get a toehold in.

Damaging the nail and surrounding tissue structures makes these infections more likely. It’s also good to wear shoes that don’t pinch your toes, like high heels tend to do. Trim your toenails straight across to help prevent an edge from becoming ingrown. Fingernails can be trimmed into a curved shaped without problems usually. Also try to keep your hangnails trimmed. Long-term exposure to water and some nail polishes can weaken the plate and cause painful splitting and peeling.  Remember that water really is the “Universal Solvent” and chronic exposure can wreck havoc on your hands. I also recommend patients make sure they are getting enough biotin in their diets. Foods like soy beans, nuts, avocados, mushrooms, and bananas will give your body the raw material it needs to grow healthy nail structures. Biotin can also be purchased for around ten dollars at most pharmacies and grocery stores. There are also clear polishes that contain proteins to strengthen your nails. 

When it comes to caring for your nails, you’ve probably heard the best advice from mom already: Don’t bite them; don’t tear at them; don’t pick them. And for my sake, please don’t run them down any chalkboards if I’m around.