Thumb suckers less prone to allergies: New Zealand study

Infants who suck their thumbs or bite their nails appear less prone to allergies as adults, New Zealand researchers have found. Researchers then followed up by giving them allergy skin prick tests when they were aged 13 and 32. The allergy level fell to 31 percent for children who did both.

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Thumb suckers less prone to allergies: New Zealand study