Q: My 10-year-old grandchild gets a bath only three times a week, and sometimes it's only twice a week. Is this normal? I thought that children should be bathed every day.
A: While it's true that the ritual of a child's nightly bath has fixed itself into the popular culture, the reality of what's best is actually somewhat different.
Back in the days before indoor plumbing and central heating, bathing was generally performed weekly in the United States. It was a family affair often performed on Saturday night, so that everyone would be their sweet-smelling best for church on Sunday.
As technological advances gave each house a furnace in the basement and hot running water in the bathroom, taking a bath was no longer a laborious chore. Add in the revolution wrought by understanding how infections are transmitted, and the link between physical cleanliness and good health was formed.
However, the zero tolerance of the medical environment doesn't transfer to the home. According to guidelines developed by the American Academy of Dermatology, your grandchild is perfectly fine with those three or even two baths per week. The reasoning is twofold.
First, unless he or she is playing in mud, crawling through public sandboxes or helping out with messy tasks, the average kid just doesn't get dirty enough to require a bath every day.
The other consideration is something known as the skin barrier. That's the protective film of cells and lipids that make up the outermost layer of your skin. Sometimes called the lipid barrier, it's meant to keep your skin hydrated by preventing water and electrolytes from evaporating.
In children, the skin barrier is not yet fully developed. Too much soap and scrubbing and they run the risk of irritation, even infection.
In addition, the skin is home to certain microbes and bacteria that are an important part of our immune systems. Daily washing diminishes their numbers.
So how often should your child be bathing?
With babies, three times a week is plenty. What's important is being vigilant about keeping the face, neck and diaper areas clean and -- this is just as important -- dry. If bath time is something your baby enjoys and you'd like to do it more often, go with just warm water and no soap.
Children between the ages of 6 and 11 should bathe at least once or twice a week. If they want to bathe more often, that's fine. Are they smelly or visibly dirty? Then they need a bath.
Once kids hit puberty, dermatologists say daily bathing is a good idea.
To get off on the right foot with personal hygiene habits, make the activities fun. This includes teeth brushing, hair brushing, hand-washing and bathing.
Toys, story times, charts with stickers or stars -- all can turn a daily chore into an enjoyable moment.
And while daily bathing up until adolescence is optional, proper hand-washing is not.
From the time they're old enough to understand, be sure to teach your kids to wash their hands before eating, after using the bathroom, after blowing their noses and, of course, when they're just plain dirty.
• Eve Glazier, M.D., MBA, is an internist and assistant professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health. Send your questions to firstname.lastname@example.org.