Nail biting habit can be hard to break; behavioral techniques can help

Tuesday, February 9, 2010

My friend Katie has a dirty little secret that's actually obvious to anyone who gives her a cursory once-over: Ever since childhood, she has bitten her nails down to the quick, often gnawing at them until the cuticles bleed, especially when she's nervous or bored. This successful 43-year-old marketing executive just can't seem to stop, no matter how many foul-tasting, jalapeƱo-laced potions she paints on her fingers or how many disapproving stares and lectures she receives from friends, family members and the odd passerby.

"The irony is that it's the first thing I notice with other people: their hands, then their teeth and their shoes," says Katie in a somewhat exasperated fashion. "I can't help thinking about how terrible it looks, and how disgusting it is that you just touched things a million other people have touched and now you're putting that finger in your mouth. Clearly, I know it's a terrible habit. But I don't know how to break myself of it."

She's not alone. Chronic nail biting, or onychophagia, most commonly begins in childhood, peaks in adolescence and then tapers off. Studies have found that between 28 and 33 percent of children between ages 7 and 10, 44 percent of adolescents and 19 to 29 percent of young adults gnaw at their fingernails. "It's a lot more common than one might think," says Baltimore County psychiatrist Carol Watkins. "The incidence gradually declines into adulthood, but we're still talking about 10 to 20 percent of grown men and women who continue to bite their nails." She adds that this behavior occurs across continents and cultures, and is slightly more prevalent among males than females.

So what's the big deal if you chomp on a nail here and there? While it may seem like a fairly innocuous habit -- most likely something you do when you're stressed, nervous, bored or perhaps even excited, often without even realizing it -- there can be ramifications, says Dupont Circle dermatologist Ella Toombs.

"It is definitely unsanitary, facilitating germ transfer from the hands and nails to the mouth," she says before shooting down a range of urban legends, such as the notion that chewed-off nails end up in your appendix, where they can cause appendicitis. "There are no real, serious, long-term medical problems caused by biting your nails, but it can be unattractive, [leading to] cosmetically unacceptable fingernail beds, with lots of redness of tissue and swelling and even scarring, in the worst cases. This type of broken skin is also more susceptible to infections."

While it's plain that a lot of people bite their nails at various points in their lives, it's less clear why.

"Initially people thought it had to do with an oral fixation -- the Freudian view -- but that's no longer popular opinion," says Watkins, who explains that there are now competing views on whether it's a learned habit, for example, or has a biological basis. "Older studies tend to talk about psychological reasons, while newer ones look at behavioral and biochemical kinds of things, such as whether [nail biting] is caused by a relative of obsessive-compulsive disorder." Some experts think there's a genetic link, since it often runs in families, while others believe it's an exaggerated grooming behavior, similar to what's seen in animals such as chimps. Regardless, there is definitely a comfort or stress-relief aspect for a lot of folks, says Watkins, although she thinks there's no single answer. "The way I see it is, [the cause] may be different in different people. You really have to look at the individual. For some people it's associated with anxiety, for example, but other studies have shown that people who bite their nails aren't that anxious."

Most people can stop biting their nails with fairly simple behavioral techniques, either on their own or with help from family members or a professional.

The key is to become aware of exactly when and where you're biting your nails, says Watkins, who suggests keeping a journal to help identify any triggers, such as feeling nervous, being in the car or absentmindedly watching TV.

Reminders such as wearing a bracelet that jingles when your hand gets close to your mouth can also increase awareness of the habit. "Once you actually realize you're doing it, then you can avoid triggers and set up competing behaviors, whether it's a relaxation technique like meditation or something else you can do instead with your hands," Watkins explains, recommending needlepoint, a stress ball or just sitting on your hands. Keeping nails short, so there's less to bite, can be a helpful deterrent, as can treating yourself to a regular manicure or wearing gloves.

If all else fails, you can turn to the Internet's favorite cure: bitter liquids that you paint on your nails, which are typically tinged with Tabasco sauce or other peppery flavors, but be aware that they can backfire among children or adults (who may learn to like the taste). Medications such as Prozac and others used to treat OCD are typically a very last resort, say experts, and only for the most severe cases, where nail biting may indicate a larger psychological problem.

While nail biting isn't the worst habit in the world and can definitely be tough to quit, it seems worth a try, if only for hygiene reasons.

For my friend Eric, the turning point came at age 39, after three decades of regularly gnawing away at his hands whenever he was nervous or anxious, under the guise of "man-grooming."

After seeing another manic nail biter with ragged, bleeding cuticles and realizing that's what people saw when they looked at his hands -- "just ugly and unattractive" -- Eric made the classic New Year's resolution to stop in 2009. So he stuck a Post-it on his bathroom mirror, making it the first thing he saw every morning, reminding him not to chomp. He'd repeat a short, related mantra 10 times in a row and then head to his laptop, which contained another Post-it that he'd see while he worked. "I thought to myself, 'I need to be really conscientious of the fact that I do this,' and it helped me quit it," says Eric. "Now, every once in a while I catch myself getting after a finger, but I stop, sit on my hands and tell myself, 'Don't be stupid, don't bite your nails over and over.' And it's still working."

Katie, on the other hand, is still in the "planning phases" of quitting but hopes to get there one day soon.

Have you had any luck kicking this dirty little habit? Share your story with us, either by sending an e-mail to health-science@washpost.comor by reading this column online at and clicking on the "comments" link at the end of the story.

© 2010 The Washington Post Company