Eczema, as defined by the World Allergy Organization (WAO) revised nomenclature in 2003, affects 15% to 20% of school children and 2% to 5% of adults worldwide. About 50% of people with eczema demonstrate atopy, with specific immunoglobulin E responses to allergens.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of topical medical treatments, and dietary interventions in adults and children with established eczema? What are the effects of breastfeeding, reducing allergens, or dietary interventions for primary prevention of eczema in predisposed infants? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
We found 54 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: breastfeeding, controlling house dust mites, corticosteroids, dietary exclusion of eggs or cow's milk, elementary diets, emollients, essential fatty oils, few-foods diet, multivitamins, pimecrolimus, probiotics, pyridoxine, reducing maternal dietary allergens, tacrolimus, vitamin E, and zinc supplements.
Eczema, as defined by the World Allergy Organization (WAO) revised nomenclature in 2003, affects 15% to 20% of school children worldwide and 2% to 5% of adults. Only about 50% of people with eczema demonstrate allergic sensitisation.
Remission occurs in two-thirds of children by the age of 15 years, but relapses may occur later.
Emollients are generally considered to be effective for treating the symptoms of eczema. However, the few small short-term RCTs that have been done so far do not confirm this. Sufficiently powered long-term RCTs are needed to clarify the role of emollients in the treatment of eczema.
Corticosteroids improve clearance of lesions and decrease relapse rates compared with placebo in adults and children with eczema, although we don't know which is the most effective corticosteroid or the most effective dosing regimen.
Topical corticosteroids seem to have few adverse effects when used intermittently, but if they are of potent or very potent strength, they may cause burning, skin thinning, and telangiectasia, especially in children.
The calcineurin inhibitors pimecrolimus and tacrolimus improve clearance of lesions compared with placebo and may have a role in people in whom corticosteroids are contraindicated. They also seem suitable for topical use in body areas where the skin is particularly thin, such as the face.
CAUTION: An association has been suggested between pimecrolimus and tacrolimus and skin cancer in animal models. Although this association has not been confirmed in humans, calcineurin inhibitors should be used only when other treatments have failed.
We don't know whether vitamin E or multivitamins reduce symptoms in adults with eczema or whether pyridoxine, zinc supplementation, exclusion diets, or elemental diets are effective in children with eczema, as there are insufficient good-quality studies.
Probiotics do not seem to reduce symptoms in children with established eczema.
Essential fatty acids, such as evening primrose oil, blackcurrant seed oil, or fish oil, do not seem to reduce symptoms in people with eczema.
We don't know whether control of house dust mites or maternal dietary restriction can prevent the development of eczema in children.
Observational data suggest that exclusive breastfeeding for at least 3 months does not reduce eczema risk and there is no evidence to suggest that exclusive breastfeeding alleviates eczema symptoms, unless a child is allergic to cow's milk protein.Introduction of probiotics in the last trimester of pregnancy and during breastfeeding may reduce the risk of eczema in the baby, although it remains unclear whether both antenatal and postnatal supplementation together yields the strongest protective effect. It is equally unclear which strains of probiotics are most effective.