In this 2002 photo, Carolina Panthers' Steve Smith, left, receives a pacifier from his 11-month old daughter Baylee. Boosting the ‘hygiene hypothesis,’ a study hints that an infant may benefit from microbes in a parent’s saliva. (Chuck Burton/AP)
allergies in children
Cleaning your child’s pacifier in your mouth may help keep allergies at bay

THE QUESTION Very young children exposed to bacteria through such experiences as playing in the dirt or living on a farm have been shown to be less likely to develop allergies. Might the method that parents use to clean an infant’s pacifier also make a child less susceptible to allergens?

THIS STUDY included 184 infants who were tested periodically for allergies until their third birthday. By the time they were 18 months old, 25 percent had eczema, 5 percent had asthma and 15 percent had developed sensitivity to allergens. When the infants’ parents were asked how they cleaned a dropped pacifier (and with more than one answer allowed), nearly all said they rinsed it in tap water, about half boiled it and half said they cleaned the pacifier by sucking on it before giving it back to the child. Children whose parents sucked on the pacifier to “clean” it, thus transferring microbes from their saliva to their children, were 37 percent less likely to have eczema or allergen sensitivity and 12 percent less likely to have asthma than were children whose parents did not do this. The rate of respiratory infections among the infants did not differ, no matter what pacifier cleaning method was used. Development of eczema remained about a third less until the children were 3.

WHO MAY BE AFFECTED? Children age 3 and younger who use pacifiers. The number of U.S. children with allergies has been rising in recent decades, with new data indicating that about 12 percent have skin allergies, 17 percent have respiratory allergies and 5 percent have food allergies. Eczema in infants is often seen as an early sign of allergies. One theory, the “hygiene hypothesis,” holds that lack of exposure early in life to germs has fueled the increasing prevalence of allergies in children.

CAVEATS Information on pacifier cleaning methods came from the parents’ responses during interviews. The study did not assess which microbes might have been transferred from parent to child via the pacifier.

FIND THIS STUDY June issue of Pediatrics.

LEARN MORE ABOUT allergies in children at www.kidshealth.
and (search for “allergies in children”).

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.