The effectiveness of probiotics for the treatment of eczema

Eczema affects up to 20% of children. Almost half of these patients develop eczema by the age of six months and most of them by the age of five years.¹

This evidence summary presents the best available evidence regarding the effectiveness of probiotics for eczema. For the full review, refer to Probiotics for treating eczema.²

Background

Eczema is characterised by chronic itchy skin and red rash. It is often linked with other diseases such as asthma, allergic rhinitis, food allergies and other family history of allergic diseases.³ The severity of eczema ranges between localised redness and itching to generalised redness with severe limitations to daily activities affecting quality of life and sleep.

A wide range of treatment is available for the management of eczema including emollients, topical steroids, antihistamines, tacrolimus and pimecrolimus, wet dressings along with avoidance of triggers. Most of these treatments can be complex and expensive with varying degree of success.⁴

People with eczema were found to have a different profile of the intestinal microflora to those with no eczema. These differences could proceed to the development of active eczema. One study noted a lower proportion of Bifido bacteria species in patients with eczema. The low composition was also associated with greater severity of the disease.⁵ Few studies showed that replacing gut flora with probiotics might act as an intervention. The current summary will present the effectiveness of using probiotics for the management of eczema.

Characteristics of the studies

Randomised controlled trials (RCTs) of probiotics for the treatment of eczema were included. Participants of any age with eczema diagnosed by a doctor were included. Interventions including ingested live micro-organisms such as bacteria, fungi or yeasts, ingested singly or in combination were included of any duration. The comparators were either placebo, control or other treatments.

Quality of the studies

Studies included in the report had low or unclear risk of bias. Overall, the quality of the evidence ranged from low to moderate due to the variability of the studies’ results. The main sources of bias were attrition bias and incomplete data.

Conclusion

Probiotics have no or little evidence in improving eczema symptoms or quality of life and should not be routinely recommended for patients with eczema.

Implications for research and practice

There was significant variability in the studies included in this review. Newer probiotics are currently available in the market and should be addressed in future studies. Larger studies addressing different groups of patients and standardised doses of probiotics are warranted to inform clinical decision-making.

Results

• The following databases were searched: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials, in the Cochrane Library, the Global Resource of Eczema Trials database, MEDLINE, Embase, PsycINFO, the Allied and Complementary Medicine Database, and Latin American Caribbean Health Sciences Literature until January 2017. The references of the included studies were also hand searched.
• The primary outcome measures were changes in participant-rated, parent-rated or principal carer-rated symptoms of eczema at the end of active treatment and changes in quality of life at the end of active treatment.
• Secondary outcome measures included changes in participant-rated, parent-rated or principal carer-rated symptoms of eczema during the six-month period after active treatment has ceased, changes in quality of life within the six-month period after active treatment has ceased, changes in the need for other eczema treatment during active treatment, adverse events and changes in the number of days lost from school or work due to eczema symptom.
• A total of 39 randomised controlled trials involving 2,599 randomised participants were included in the review. Six of these studies addressed adults and the rest were for children. The interventions included probiotics of the Lactobacillus and Bifido bacteria species, which were taken alone or combined with other probiotics, and were given with or without prebiotics. The duration of treatment ranged from four weeks up to six months and follow-up time was up to 36 months.
• Probiotics made little or no difference in participant- or parent-rated symptoms of eczema based on 13 studies with a total of 754 participants. Symptom severity on a scale from 0 to 20 was 0.44 points lower after probiotic treatment based on moderate quality evidence (95% confidence interval (CI) -1.22 to 0.33).
• Probiotics did not make a difference in quality of life for patients with eczema based on six studies and 552 participants with low-quality evidence (standardised mean difference (SMD) 0.03, 95% CI -0.36 to 0.42).
• Probiotics slightly reduced investigator-rated eczema severity scores in 24 studies with a total of 1,596 participants. On a scale of 0 to 103 for total Severity Scoring of Atopic Dermatitis (SCORAD), a score combining investigator-rated eczema severity score and participant scoring for eczema symptoms of itch and sleep loss was 3.91 points lower after probiotic treatment compared to control group based on low quality of evidence (95% CI-5.86 to -1.96).
• Adverse events reported were gastrointestinal related events. There was no significance difference between the occurrences of adverse events in both groups. This was based on low-quality evidence from seven studies with a total of 402 participants ((RR) 1.54, 95% CI 0.90 to 2.63).
• There was a wide range of variability in the studies’ results.

References

1. Lamb SR, Rademaker M. Pharmacoeconomics of drug therapy for atopic dermatitis. Expert Opinion on Pharmacotherapy 2002;3(3):249–55. At: https://www.ncbi.nlm.nih.gov/pubmed/11866675
2. Makrgeorgou A, Leonardi-Bee J, Bath-Hextall FJ, Murrell DF, Tang MLK, Roberts A, Boyle RJ. Probiotics for treating eczema. Cochrane Database of Systematic Reviews2018, Issue 11. Art. No.: CD006135. DOI: 10.1002/14651858.CD006135.pub3. At: https://www.cochrane.org/CD006135/SKIN_probiotics-treating-eczema
3. Beck LA, Leung DY. Allergen sensitization through the skin induces systemic allergic responses. Journal of Allergy & Clinical Immunology 2000;106(5 Suppl):S258–63. At: https://www.ncbi.nlm.nih.gov/pubmed/11080741
4. Eichenfield LF, Stein Gold LF. Addressing the immunopathogenesis of atopic dermatitis: advances in topical and systemic treatment. Seminars in Cutaneous Medicine and Surgery 2017;36(2 Suppl 2):S45–8. At: https://www.ncbi.nlm.nih.gov/pubmed/28654711
5. Watanabe S, Narisawa Y, Arase S, Okamatsu H, Ikenaga T, Tajiri Y, et al. Differences in fecal microflora between patients with atopic dermatitis and healthy control subjects. Journal of Allergy and Clinical Immunology 2003;111(3):587–91. At: https://www.ncbi.nlm.nih.gov/pubmed/12642841
6. Simonyte Sjödin K, Vidman L, Rydén P, West CE. Emerging evidence of the role of gut microbiota in the development of allergic diseases. Current Opinion in Allergy and Clinical Immunology 2016;16(4):390–5. At: https://www.ncbi.nlm.nih.gov/pubmed/27253486