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Healthy Kids: Nail biting and thumb sucking

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FORT MYERS, Fla.- According to a new study from New Zealand, children who bite their nails and suck their thumbs may be less likely to develop allergies as they grow up. Dr. Annette St. Pierre-MacKoul stopped by the studio to talk about the study and what you can do if your child has these habits.

Hygiene Hypothesis:
  • Bad habits: thumb sucking and nail biting
  • Children are exposed to more microbes
  • This alters their immune function and decreases chances of allergies


  • Do not recommend or encourage nail biting or thumb sucking
  • Parents should not stress if their children have these bad habits
  • Hygiene Hypothesis is correct
  • Exposure to microbes as a child decreases your risk of developing allergies