Eczema — an itchy, red rash that can occur anywhere on the body — is the most common skin condition, affecting 5 to 20 percent of children and 2 percent of adults at any time. While there is no cure, a number of studies have examined whether probiotics might help relieve eczema symptoms, but a review of 12 randomized controlled studies involving nearly 800 patients says it isn’t so.
According to the review, there is not strong enough evidence to suggest that probiotics are an effective treatment for eczema. In addition, the authors noted a small risk of adverse events with probiotics use.
In theory, probiotics are “good” bacteria that promote healthy digestion and give a boost to the immune system, which some researchers believe could help with conditions unrelated to digestion, such as eczema.
“The studies to date have only evaluated a limited range of probiotic strains; therefore, it is possible that as yet unstudied strains, particularly non-Lactobacillus strains, may be effective for the treatment of eczema,” said lead review author Robert John Boyle.
Boyle works out of the allergy and clinical immunology department at the Royal Children’s Hospital in Australia.
According to Boyle, there is a limited range of eczema treatments that are highly effective for most eczema sufferers. “Rarely, we see people with severe eczema that is resistant to the standard treatments,” he said, noting that those people would really benefit from a breakthrough treatment option. “So far probiotics don’t seem to be that breakthrough,” he added, “but it is important to keep pursuing the investigation of new therapies for eczema treatment.”
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.
Of the review studies, five showed no significant improvement in parent-rated symptom scores for 313 participants, although symptom severity on a scale from zero to 20 was almost a point lower after probiotics treatment compared to placebo. Three studies involving 150 participants found no significant difference in participant- or parent-rated overall eczema severity.
In seven studies where investigators rated eczema severity with probiotics compared to placebo, severity was 2.46 points lower after probiotics on a scale of zero to 102, but the drop was not statistically significant.
As for side effects, the reviewers say there are “some case reports of infections and bowel ischemia [a colon condition] caused by probiotics.”
Naturopathic doctor Cara MacMullin, of Totum Life Science in Toronto, said that the review is limited by its reliance on randomized controlled trials. “Since RTCs are essentially based on a pharmaceutical model that measures a single intervention and the results, I find in general they are not clinically reflective,” she said. “In essence they obliterate the individual.”
However, Boyle said the review authors went beyond the call of the paper to obtain original data from the authors of five of the studies. They used the data to pull out patient-oriented outcomes that they would not have had access to otherwise.
“We have therefore maximized the power of this systematic review to detect any real differences between probiotics and placebo treatment,” he said. “This strengthens our conclusions that probiotics are not an effective treatment for established eczema.”
However, MacMullin said that “from the perspective of naturopathic medicine and clinically, probiotics are only one of many potential treatments used for eczema.”
Other possible treatments include anti-inflammatory medications, elimination diets and food sensitivity testing. “It is crucial to conduct an individual assessment and provide an individualized treatment,” MacMullin said.
She said that studies have shown that probiotics are effective in immune modulation, but that there are other treatments clinicians should use concurrently with probiotics. “I find this review to not be of much importance, as it is approaching eczema treatment from the wrong perspective,” she said.
Boyle said, however that the review “highlights the failure of probiotics to impact on established eczema, but also highlights the potential for unstudied probiotic strains to have a positive effect.”
The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions.
Boyle RJ, et al. Probiotics for treating eczema (Review), Cochrane Database of Systematic Reviews 2008, Issue 4.
Source: Health Behavior News Service