We do have to pick our battles at home. As a pediatrician I’ve never gotten too excited about advising parents to spend a lot of energy trying to rid your child of the thumb-sucking or nail biting habit. In general parents aren’t successful — peers are. Often it’s when friends or peers bring the habits up that children are motivated to stop. We can help support them by reminding them when hands are in their mouth or even having them place socks on their hands while watching television as that’s a common time for the behavior. Although many parents worry about their children sucking their thumbs and fingers, it’s a common habit, with some studies finding almost 25% of children do. Much time is spent thinking about ways to help our children quit, worrying whether germs on their hands will translate to illness and hoping it doesn’t affect their teeth. A new study today this week in Pediatrics highlights perhaps a positive effect of thumb sucking. It’s worth a mention.

Allergy Protection From Thumb-Sucking And Nail-Biting?

The study evaluated children between age 5 and 11 and their later diagnoses of hay fever, allergy skin prick testing and asthma. The premise of the study builds off the somewhat controversial concept of the hygiene hypothesis. The basic premise of the hypothesis is that germ exposure early in life can contribute to how our immune system responds as we grow and develop. We may build up tolerances and immunity that conform us into less allergic people if we have different bacteria and germs around. Basically, living in a sterile environment may not be “safer” as some believe lots of dirt, bacteria, and germs early and maybe not so many sensitivities later…

In the past theories for the hygiene hypothesis have supported a decrease risk of asthma (dirt and germs coming in from and on pets may decrease allergies or asthma later) and a small 2013 study a couple years back found those children who had parents who “cleaned” the pacifier with their own mouth may be less likely to develop allergies (theory was the bacteria transfer from mom/dad’s spit to baby changed their pattern of exposure to bacteria and possibly a tendency away from allergies and asthma later). So some researchers looked a the effects of children who have their hands in their mouths more to see if any protection comes of it — they evaluated data spanning from childhood to adulthood.

The study out this week from New Zealand followed participants from young childhood (age 5) out to adulthood (age 32 years). They found that children who suck their thumbs/fingers or bite their nails are less likely to have positive allergy skin tests when a teen and also when in their 30’s. The nail-biting and thumb-sucking unfortunately didn’t decrease risks for hay fever or asthma later in life.  Their hygiene hypothesis may be somewhat true: exposure to dirt and germs from your hands in your mouth early in life may your increase your tolerance and changes your immune system. May make us more tolerant of common allergies (cats, dust mites, etc). A relief to those parents perhaps who really worry about the habits.

The reminder here? Maybe there is some protection from a natural self-soothing habit like thumb-sucking.

Thumb Sucking Tips For Parents

  • You don’t have to stop it. This is just one way infants and children self-soothe and calm. If they are being teased or you’re worried about infections on their hands or skin, then work to guide them away from the habits when they slip.
  • Putting too much pressure on your child to stop may cause more harm than good. Any reinforcement is reinforcement so even if you’re nagging and providing negative reinforcement you may embolden the habit.
  • No question that thumb-sucking (and prolonged pacifier use after age 2 years) can have an adverse affect on tooth alignment — it can buck teeth forward. So can pacifiers (especially if prolonged use or the wrong sized pacifier). If your child stops sucking on a pacifier or his thumb or fingers before his permanent front teeth come in, there’s a good chance his bite will correct itself as the teeth are still fairly moveable in the jaw.

Quitting Thumb Sucking & Pacifiers

  • Children typically quit sucking their fingers due to peer not parent pressure. Children often will stop the habit themselves once prompted by peers.
  • Praise & reward your child when they don’t suck their thumb or use the pacifier if that helps them feel confident. If you’re trying to rid your child of the pacifier, I suggest doing it cold turkey around or before age 2 years. After a few days and a couple replacement or soothing toys, things typically go very well!
  • Keep their hands busy or distract her with things she finds fun if you have a school-age child motivated to quit. Reward great success (temporary tattoos, nail polish, a special trip to the park).
  • No matter what method you try, be sure to explain it to your child and enlist them as a partner. None of us want to be a nag, least of all our children.