Systematic review of treatments for atopic eczema

Atopic eczema is the commonest inflammatory skin disease of childhood, affecting 15-20% of children in the UK at any one time. Adults make up about one-third of all community cases. Moderate-to-severe atopic eczema can have a profound effect on the quality of life for both sufferers and their families. In addition to the effects of intractable itching, skin damage, soreness, sleep loss and the social stigma of a visible skin disease, other factors such as frequent visits to doctors, special clothing and¿the need to constantly apply messy topical applications all add to the burden of disease. The cause of atopic eczema is unknown, though a genetic pre-disposition and a combination of allergic and non-allergic factors appear to be important in determining disease expression. Treatment of atopic eczema in the UK is characterised by a profusion of treatments aimed at disease control. The evidential basis of these treatments is often unclear. Most people with atopic eczema are managed in primary care where the least research has been done.

The objectives of this scoping review are two-fold. To produce an up-to-date coverage 'map' of randomised controlled trials (RCTs) of treatments of atopic eczema. To assist in making treatment recommendations by summarising the available RCT evidence using qualitative and quantitative methods.

Data sources included electronic searching of MEDLINE, EMBASE, the Cochrane Controlled Clinical Trials Register, the Cochrane Skin Group specialised register of trials, hand-searching of atopic eczema conference proceedings, follow-up of references in retrieved articles, contact with leading researchers and requests to relevant pharmaceutical companies.

Only RCTs of therapeutic agents used in the prevention and treatment of people with atopic eczema of any age were considered for inclusion. Only studies where a physician diagnosed atopic eczema or atopic dermatitis were included.

Data extraction was conducted by two observers onto abstraction forms, with discrepancies resolved by discussion.

The quality assessment of retrieved RCTs included an assessment of: a clear description of method and concealment of allocation of randomisation, the degree to which assessors and participants were blinded to the study interventions, and whether all those originally randomised were included in the final main analysis.

Where possible, quantitative pooling of similar RCTs was conducted using the Cochrane Collaboration's methods. Where statistical heterogeneity was found, sources of heterogeneity in terms of study participants, formulation or posology of intervention, and use of co-treatments were explored. Where pooling was not deemed to be appropriate, detailed descriptions of the study characteristics and main reported results were presented along with comments on study quality.

A total of 1165 possible RCTs were retrieved in hard copy form for further scrutiny. Of these, 893 were excluded from further analysis because of lack of appropriate data. The 272 remaining RCTs of atopic eczema covered at least 47 different interventions, which could be broadly categorised into ten main groups. Quality of reporting was generally poor, and limited statistical pooling was possible only for oral cyclosporin, and only then after considerable data transformation. There was reasonable RCT evidence to support the use of oral cyclosporin, topical corticosteroids, psychological approaches and ultraviolet light therapy. There was insufficient evidence to make recommendations on maternal allergen avoidance for disease prevention, oral antihistamines, Chinese herbs, dietary restriction in established atopic eczema, homeopathy, house dust mite reduction, massage therapy, hypnotherapy, evening primrose oil, emollients, topical coal tar and topical doxepin. (ABSTRACT TRUNCATED)