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Child & Teen Health

Fewer allergies: A possible upside of thumb sucking and nail biting

July 19, 2016

About the Author

photo of Claire McCarthy, MD

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio
View all posts by Claire McCarthy, MD


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Dee Bonz
August 19, 2016

I am 32, a mother of 3 and I still suck my thumb. We exist all around you, but the stigma keeps us all quiet in front of you. Everytime I am honest in public about it I have several people speak up about their family member or self being an adult thumbsucker.

July 24, 2016

I have zero allergies and still suck my thumb (am quite the adult). Good news…finally! 🙂

D. Rangaswamy
July 23, 2016

Thanks, the article puts me at rest. I have been worried about the nail bitkng habit of my little one.

July 20, 2016

“When they tested at 13 for allergies to common things such as dust, grass, cats, dogs and molds, they found that 38% of those who had an “oral habit” tested positive — whereas 49% of those who didn’t suck their thumbs or bite their nails tested positive”
Who tested positive, exactly? 🙂

July 20, 2016

There are two groups:
1) Oral Habit
2) No Oral Habit

After testing, they found that 38% of group [1] had tested positive for allergies. They ALSO found that 49% of group [2] tested positive for allergies!
So, a percentage of both groups tested positive. Hope this helped!

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