Antibiotics are often necessary to treat an infection, but kids who take them before they’re a year old appear to be more likely to develop eczema.
A report published in the British Journal of Dermatology resulted from a review of earlier research. It concluded that children who took antibiotics in their first year were about 40% more likely to develop the itchy skin disorder. As interpreted in a story by Reuters, the study supports the idea that antibiotics destroy intestinal microbes that contribute to the development of the immune system after birth.
Fetuses exposed to antibiotics taken by their pregnant mothers, however, were not at higher risk of getting eczema after birth.
The Dermatology report, the first to consolidate available results from several studies indicating that early-life exposure to antibiotics increases the risk of eczema, reinforces what’s known as the “hygiene hypothesis”—that babies and youngsters who are not exposed to a wide variety of microbes don’t develop immune systems as robust as those who are. The theory has been applied to immune overreactions such as allergies and asthma.
As we wrote a few months ago, the American Academy of Pediatrics issued new guidelines for diagnosing and treating children’s ear infections in an effort to reduce the unnecessary use of antibiotics because, in addition to helping bacteria develop resistance to the drugs, using antibiotics when they’re not necessary can cause stomach problems and allergic reactions.
For some infections, most kids improve within a couple of days without drug intervention.
As many as 2 in 10 kids will have symptoms of eczema; more than half of them continue to have symptoms into adulthood.
The new report analyzed results of 20 studies of antibiotic use, either prenatally or in the first year of life, and their association with later skin problems. The more antibiotics a baby took, the higher the risk. Each round of antibiotics bumped up the risk of eczema by 7%. Broad-spectrum antibiotics, or those that treat a wide variety of infections, like amoxicillin, seemed to have the strongest effect.
Some experts noted the possibility of "reverse causation”—that’s when a baby with eczema has more skin infections that might require antibiotics and confound the results of the studies. But the authors of the new review acknowledged that limitation and said the findings are still valid.
Another possible flaw in the review concerns when eczema symptoms began and when antibiotics were first administered. The onset of eczema often occurs before a baby is a year old, so if symptoms began before antibiotics were given, those children should have been excluded from the studies.
But even outside experts who pointed out that flaw agreed: Antibiotics should be given to anybody only when it’s necessary, and especially for wee ones whose immune systems are developing.