Topical Probiotics Reduce Atopic Dermatitis Severity: A Systematic Review and Meta-Analysis of Double-Blind, Randomized, Placebo-Controlled Trials.

Atopic dermatitis (AD) is a chronic skin disease that commonly appears during childhood but can present at any age. There are interventions that are effective in treating AD in children, but it has been difficult to find effective treatments for adults. This systematic review and meta-analysis sought to determine the efficacy of topical probiotic treatment for AD in adult populations. A database search was conducted of peer-reviewed, double-blind clinical trials, and studies underwent a systematic exclusion and inclusion process, yielding four that met the criteria. Disease severity, as measured by a standardized scoring tool SCORAD (SCORing Atopic Dermatitis), was culled from each study and compared to placebo at two-week and four-week time points. All studies showed improvement in SCORAD in the treatment groups compared to baseline at all time points. Two showed significant decreases in SCORAD after two weeks of treatment, and three studies showed long-lasting improvement after four weeks of treatment. Interestingly, while each study showed a reduction in the severity of AD at the two- and four-week time points, a pooled meta-analysis did not show a statistically significant difference between treatment and control at four weeks of treatment. Clinically, there may be benefits to topical probiotic usage as evidenced by the individual studies; more studies need to be performed including adults to show statistical significance.