Allergic eczema, or atopic dermatitis, is a skin disease combining cutaneous dryness and itching. Not contagious, this cutaneous condition is made more likely by a predisposition to allergies, in which microbiota plays an important role.
About this article
Three times more common than 30 years ago, today, eczema affects up to 20% of children. It has become the most common childhood cutaneous condition in industrialized countries. However, in the majority of cases, eczema disappears in adolescence, and only 10 to 15% of patients remain affected throughout their lives.
An excessive immune response
Eczema is related to a genetic predisposition that alters the skin barrier. This alteration paves the way for allergens to penetrate into the skin, which causes an excessive immune reaction. Changes in the composition and diversity of the intestinal and cutaneous microbiotas observed in these patients may also be involved.
Eczema manifests very early in infancy (between 1 and 3 months) by rough, dry skin, and the appearance of very itchy red patches during inflammatory flares.
Limit skin irritation
Treatment for eczema primarily tries to limit skin irritation (wearing cotton clothes, using gels without soap, being gentle when washing your skin, etc.) and to reduce cutaneous lesions with hydrating creams and topical steroids. In the most severe cases, the doctor may prescribe short-term antihistamines.
Probiotics improve symptoms
Another approach: correct the dysbiosis (imbalance in bacterial flora) by modifying the intestinal and cutaneous microbiotas. Several studies have shown that probiotics improve eczema symptoms (particularly certain lactobacilli) and reduce intestinal inflammation in affected babies. Given as a preventative treatment to pregnant women, they could reduce the frequency of symptoms in their baby.
Nutten S. Atopic Dermatitis: Global Epidemiology and risk Factors. Ann Nutr Metab 2015;66(suppl 1):8-16
La dermatite atopique. Inserm. Mis à jour mars 2016 http://www.inserm.fr/layout/set/print/thematiques/physiopathologie-metabolisme-nutrition/dossiers-d-information/dermatite-atopique
Wang M, Karlsson C, Olsson C, et al. Reduced diversity in the early fecal microbiota of infants with atopic eczema. J Allergy Clin Immunol 2008 ; 121 : 129-34.
Ismail IH, Oppedisano F, Joseph SJ, et al. Reduced gut microbial diversity in early life is associated with later development of eczema but not atopy in high-risk infants. Pediatr Allergy Immunol 2012 ; 23 (7) : 674-81.
Candela M, Rampelli S, Turroni S, et al. Unbalance of intestinal microbiota in atopic children. BMC Microbiol 2012 ; 12 : 95.
Grice EA, Segre JA. The skin microbiome. Nat Rev Microbiol. 2011 Apr; 9(4): 244-253.
Kalliomaki M, Salminen S, Poussa T, et al. Probiotics and prevention of atopic disease: 4-year follow-up of a randomised placebo-controlled trial. Lancet 2003 ; 361: 1869-1871.
Kalliomaki M, Salminen S, Poussa T et al. Probiotics during the first 7 years of life: a cumulative risk reduction of eczema in a randomized, placebo-controlled trial. J Allergy Clin Immunol 2007 ; 119: 1019-1021.
Boyle RJ, Ismail IH, Kivivuori S, et al. Lactobacillus GG treatment during pregnancy for the prevention of eczema: a randomized controlled trial. Allergy. 2011;66(4):509-516.