Early-onset atopic dermatitis [AD] in children appears to have a different phenotype than AD in adults, which may open new therapeutic avenues and targeted treatment in this population, researchers report in The Journal of Allergy and Clinical Immunology (Sept. 23, 2016).
Investigators assessed skin biopsy specimens from 19 children with AD. The children were younger than five years of age, and the samples were taken within six months of the onset of disease. The biopsies were compared using immunohistochemistry and quantitative real-time PCR to biopsies from adults with AD or psoriasis, and pediatric and adult controls.
Lesional skin in children with AD had as much or more epidermal hyperplasia and cellular infiltration than was seen in adults with AD.
As well, there were two quite surprising findings.
First, while the skin of adults with AD is typically deficient in the naturally produced anti-microbial factors that fight staph infections and certain viruses—a deficiency thought to be a significant contributor to the high risk of these infections in AD—the levels of these antimicrobial factors in the skin of young children with eczema was very high.
Secondly, while the skin of adults with AD is deficient in the protein filaggrin—a deficiency which has been considered a significant factor in the damaged skin barrier function in these individuals—the authors found that while the children with AD had impaired barrier function, they had filaggrin expression comparable to healthy children. Therefore, filaggrin-targeting therapies may be less beneficial for restoring skin barrier function in young AD patients, the authors note.
“Our findings offer new directions for targeted therapies for children with eczema,” co-senior author Dr. Amy Paller, dermatologist at Ann & Robert H. Lurie Children’s Hospital of Chicago, and chair of dermatology and professor of pediatrics at Northwestern University Feinberg School of Medicine, said in a press release. “While some characteristics of eczema in children are the same as in adults, our study showed substantial differences that are important for understanding eczema in children and developing tailored treatments that maximize effectiveness and minimize potential side effects.”
The investigators compiled panels of data from the blood and skin samples of each participating child with AD. “Our study is the first step toward personalized medicine for children with eczema,” said Dr. Paller. “We need to collect much more data to start matching targeted treatments to an individual’s specific disease characteristics.”