Thumb-sucking, nail biting kids will develop fewer allergies

Good news for parents who often have to struggle in getting their young toddlers to quit thumb sucking, as a new study has found that children who are thumb-suckers or nail-biters are less likely to develop allergic sensitivities.

Mcmaster University researchers have found that common childhood habits of thumb-sucking and nail-biting would increase microbial exposures, affecting the immune system and reducing the development of allergic reactions also known as atopic sensitization.

Lead researcher Malcolm Sears of McMaster University’s Michael G. DeGroote School of Medicine said, the findings are consistent with the hygiene theory that early exposure to dirt or germs reduces the risk of developing allergies.

“While we don’t recommend that these habits should be encouraged, there does appear to be a positive side to these habits,” he added.

The habits of thumb-sucking and nail-biting were measured in a longitudinal birth cohort of more than 1,000 New Zealand children at ages 5, 7, 9 and 11 and atopic sensitization was measured by skin-prick testing at 13 and 32 years old.

The researchers found that 31 per cent of children were frequent thumb suckers or nail biters.

Among all children at 13 years -old, 45 percent showed atopic sensitization, but among those with one oral habit, only 40 percent had allergies. Among those with both habits, only 31 percent had allergies.