Motley Zoo

In 2007, NYU Langone Medical Center scientists made the surprising discovery that our skin hosts hundreds of species of bacteria—a motley zoo that’s much more diverse than previously thought. Moreover, these species differ markedly from one individual to another and also vary over time. While a few of the identified bacteria are known to be potentially harmful and a few beneficial, what the rest are doing to us—or for us—remains a mystery.

If the NYU Langone team didn’t solve this puzzle, they did raise an intriguing thought: perhaps the composition of the skin’s flora plays a significant and underappreciated role in the maintenance of healthy skin. If so, it might be possible to control stubborn, chronic diseases like eczema and psoriasis by managing our skin’s microbial mix.

In a step toward developing this new paradigm, researchers led by Seth Orlow, MD, PhD, the Samuel Weinberg Professor of Pediatric Dermatology and chair of the Ronald O. Perelman Department of Dermatology, have launched a study comparing the skin bacteria of young children with atopic dermatitis (AD) with that of children who are disease free. The most common form of eczema, AD is characterized by red, itchy blotches on the face and body folds. It typically begins in infancy and affects up to one in five children, many quite severely. There’s no cure and few effective treatments, though many children eventually outgrow the worst of the disease.

“We do a pretty good job of helping children with AD, but there are still many patients whose AD is not well managed,” says Dr. Orlow. His collaborators include the research team of Martin Blaser, MD, the Frederick H. King Professor of Medicine and chair of the Department of Medicine, and leader of the 2007 study, which was funded in part by a generous gift from Diane Belfer; as well as Julie Schaffer, MD, director of pediatric dermatology, and Mercedes Gonzalez, MD, a dermatology resident.

The researchers will identify the skin’s flora using sophisticated gene-analysis techniques. All that’s required of the children is a simple skin swab. In addition, the study, which is supported in part by a generous gift from the Manzo family, will examine how the skin’s mix of microbes change after treatment with topical corticosteroids, one of the most effective therapies for AD .

Most people with the condition are colonized by Staphylococcus aureus, a bug implicated in a variety of skin infections. The more staph they have, the worse the AD. It’s also known that staph can stimulate an immune response that aggravates already inflamed skin. Yet despite these links, staph-fighting antibiotics aren’t very effective against AD. “Right now, all antimicrobial AD treatments are focused on staph,” notes Dr. Orlow. “Perhaps we’ve been picking the wrong microbes.”

If other bacteria are implicated, it could significantly impact how AD is treated. “AD seems to result from many factors,” Dr. Orlow explains. “We know there’s a genetic component—a mutation in a gene called filaggrin, which is responsible for maintaining the integrity of the skin’s top layer—and there’s also an immunological component.” Some or all of these factors conspire to disrupt the skin’s barrier and cause inflammation, paving the way for AD.

The hope, adds Dr. Orlow, is that early intervention with precisely tailored antimicrobial therapy, or perhaps even inoculation with beneficial bacteria, could interrupt this cycle and calm the inflamed skin. If so, then this is one excursion to the zoo that will delight countless children.