A Thumb’s Up for Thumb-Sucking?

A recent study says there may be a link between childhood thumbsucking and fewer allergies in later life. Should you encourage it?

It’s a sight that rattles the nerves of some parents: a child who loves to suck his thumb or bite her nails.

Turns out it’s a self-soothing behavior for these children – and here’s some news that might help soothe the nerves of their parents, too.

A recent study, published in the July issue of Pediatrics, says there may actually be a positive to what many parents see as bad habits. The study, part of a long-term research project in New Zealand, showed that children who sucked their thumbs or bit their nails were about 22 percent less likely later on to develop allergies to dust mites, grass, pets and some other common allergens.

Still, the habit is distressing to most parents.

“Any parent who’s trying to get their child to stop thumbsucking or nail biting will tell you how difficult it is,” said LeighAnn Riemer, DO, of Briarpatch Pediatrics, which has offices in Sandwich and Yarmouthport.

“The general view among pediatricians is that as long as they stop by 5 years old, it’s normal to help them soothe themselves.”

Encourage the Wanted Behavior

It’s best for parents to learn to ignore the habit, as hard as that might be, according to Dr. Riemer.

“With children, if you want things to continue, you give them positive reinforcement,” she said. “If you want them to stop something, ignoring it is the best idea, especially when they’re younger than 5.”

Usually thumbsucking and nail biting stop without the intervention of parents or pediatricians.

“They go away once they start school, especially thumbsucking, when they’re around their peers who aren’t doing it during the day,” said Dr. Riemer. “They may still do it at night, because it helps them go to sleep. It’s a soothing mechanism. We tend to say, if they want to do it, they can do it.

“It’s frustrating because parents want thumbsucking and nail biting to stop and there’s no way to get it to stop until the child is ready.”

It’s very unusual for there to be any bad effects from thumb-sucking or nail-biting, said Dr. Riemer.

“There are some children who have dental consequences,” she said. “A dentist can help by putting appliances in the mouth that will stop the thumb-sucking.

“Biting can cause nail infections, but that’s also rare. We don’t recommend putting the nasty-tasting nail polish on the nails or anything like that. You ignore it and it will eventually go away. No real intervention is recommended at all.

Despite the news from the recent study that thumbsucking and nail biting may actually have some health benefits, parents should not encourage children to take up thumbsucking or nail biting, Dr. Riemer said. But it does mean there might be an unexpected benefit to those habits.

“It’s a good positive outlook to offer parents who are trying to get their child to stop thumbsucking or nail biting and who are frustrated because it’s hard to stop this habit,” she said.

She pointed out that the study was small and she’d like to see if future studies showed the same results. She pointed out that it ties in with “the hygiene hypothesis,” which suggests that early exposure to germs can help build immunity.

“There have been a lot of studies talking about the hygiene hypothesis, which are saying we’re far too clean in our society and that having some exposure to different bacteria is helping your immune system to defend against allergies. It’s interesting to see another study along those lines.”

A Thumb’s Up for Thumb-Sucking?