Pediatrician News Blog

Recent Health News #1 – Nail-biting, Thumb-sucking and The Hygiene Hypothesis

Nail-biting, Thumb-sucking and The Hygiene Hypothesis

Are those annoying habits actually good for our kids?

New information published in The Journal of Pediatrics this summer:

Study Purpose: “We tested the hypothesis that children who suck their thumbs or bite their nails have a lower risk of developing atopy, asthma, and hay fever in a population-based birth cohort followed to adulthood.

Study Design: Prospective study of 1037 children in New Zealand from infancy to 38 years of age. Parent responses to questions about thumb-sucking and nail biting in childhood (5-11 years of age) were recorded. The children were tested for skin sensitivities (atopy) to skin-prick tests at 13 years of age. They were followed into adult hood to collect data about development of asthma and hay fever as young adults.  


  • At least 31% of the children surveyed had either a habit of thumb-sucking or nail-biting (oral habit).
  • Of the children who were skin tested (724 out of the original 1037) 45% were atopic (skin allergic). Of the children who had an oral habit, 38% showed positive skin test results compared to 49% of those who did not have an oral habit.
  • There was no statistical difference in the adult asthma and hay fever outcomes for the groups with or without oral habits during childhood.

2 different views on some new information published in The Journal of Pediatrics this summer:


My Two-Cents

I’ve had many teen check-ups go like this over the years:


“Mrs. _____, I would like to talk with your teenager for just a short time alone if you don’t mind. I don’t want him to be embarrassed to ask me questions that might be on his mind. But before we move to a different room, are there any specific concerns you have about him that we have not already covered?”



“Yes, Doc. Could you tell him to stop biting his nails, please?”



“Sure, we can talk about hygiene. It’s really important for a teenager.”


Then we go to another room and the teenager begins to tell me all about his concerns which may include really serious issues like depression, self-cutting, sexual experimentation, marijuana use that the parent knows nothing about.


So, here’s my advice, parents: let’s not miss the forest for the trees! When we pick on our kids over and over about small things that are really not that important in the grand scheme of life, they do not feel accepted by us. Eventually they will tune us out. Doors of communication close and serious issues can arise. Try asking your child or teen about something you know really interests HIM even if you are not very intrigued by the topic. Just letting him talk about things he likes will show you care and will keep doors of communication open. Let’s all listen a little more closely and find a way to relate to our kids today (myself included)!


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