Effects of Probiotics on Atopic Dermatitis: A Randomised Controlled Trial
Authors: Perry Tamara T. 
Published: September 2006

Purpose of the Study.
To examine the effects of probiotics on moderate-to-severe atopic dermatitis (AD) in young children.

Study Population.
Fifty-six children (aged 6–18 months) with moderate-to-severe AD (a modified scoring AD [SCORAD] index of ≥25). Patients were excluded if they had previous exposure to probiotics, were currently taking antibiotics, or had other major medical problems.

Methods.
Study participants were randomly assigned to receive probiotics (1 × 109 colony forming units Lactobacillus fermentum) or placebo twice daily for 8 weeks. Patients were stratified and block-randomized by SCORAD index, topical corticosteroid potency, and age. Participants were evaluated at baseline and weeks 2, 4, and 8 of the intervention period, with a final postintervention evaluation at week 16. The primary outcome measure was change in AD extent and severity as assessed by the modified SCORAD index. Secondary outcome measures included (1) change in family quality of life, (2) change in topical corticosteroid use, and (3) parental impression of the intervention.

Results.
The SCORAD index of the children in the intervention group was significantly reduced over time compared with those in the placebo group, and the effect continued 2 months after the intervention was completed. Statistically significant improvement over baseline was seen in 92% of the intervention participants compared with 63% of children in the placebo group. Secondary outcome measures were not significantly different between groups. There were significantly fewer reported lower respiratory tract infections in the intervention group and no clinically significant adverse events recorded in either group.

Conclusions.
Probiotics are beneficial in decreasing severity and extent of moderate-to-severe AD among children &lt;2 years old.

Reviewer Comments.
This is the first study to examination the effects of probiotics among young children with moderate-to-severe AD (mean SCORAD index: 41); previous studies examined children with milder disease (mean SCORAD index: 16). Similar to previous reports, the current study found significant improvements in objective signs of disease in terms of severity and extent. However, there were no significant differences in parental subjective observations or topical steroid use. The chronic nature of AD makes it difficult to assess subtle changes in quality of life or parental perceptions of disease in such a short period of time. It is possible that improvements in subjective findings and medication use would have been more evident if the study period was longer. There was a considerable placebo effect, and although statistically insignificant, more than half of the participants receiving placebo showed improvement at the end of the study period. This effect was likely, in part, because of improved adherence with medications as a result of being in the study. Future long-term studies should be conducted in this population to further assess long-term efficacy, changes in quality of life, medication use, and effects on development of other atopic diseases such as allergic rhinitis and asthma.