Dietary Supplements for Established Atopic Eczema

Summary

A Cochrane review [Abstract] 1 included 11 studies with a total of 596 subjects. Two studies assessed fish oil versus olive oil or corn oil placebo. The following were all looked at in single studies: oral zinc sulphate compared to placebo, selenium versus selenium plus vitamin E versus placebo, vitamin D versus placebo, vitamin D versus vitamin E versus vitamins D plus vitamin E together versus placebo, pyridoxine versus placebo, sea buckthorn seed oil versus sea buckthorn pulp oil versus placebo, hempseed oil versus placebo, sunflower oil (linoleic acid) versus fish oil versus placebo, and DHA versus control (saturated fatty acids of the same energy value). Two small studies on fish oil could be pooled.

With regard to primary outcome 'Changes in participant-rated or parent-rated symptoms of atopic eczema, such as itching (pruritus) or sleep loss in the short term', no data were available.With regard to primary outcome 'Degree of long-term (over six months) control, such as reduction in number of flares or reduced need for other treatments', there was no significant difference in antihistamine or topical steroid use.

With regard to secondary outcome 'Global severity as rated by the participants or their physician', analysis of total symptom score as rated by the participant showed significantly higher overall improvement in the fish oil group, compared to the control group (one study; MD 10.00, 95% CI 0.14 to 19.86). Analysis of total symptom score as rated by the physician showed no significant difference in overall improvement when fish oil was compared to placebo.With regard to secondary outcome 'Quality of life', there was a significant difference in effect of daily living as evaluated by participants at the end of treatment in favour of fish oil (treatment group), compared to placebo (2 studies; MD -0.84, 95% CI -1.52 to -0.15).

With regard to our tertiary outcome measure 'Changes in individual signs of atopic eczema as assessed by a physician', no significant difference was found for erythema (2 studies; MD 0.38, 95% CI -0.36 to 1.13), excoriation (1 study; MD 0.40, 95% CI -1.24 to 2.04), lichenification (2 studies; MD 0.04, 95% CI -0.70 to 0.78), severity (1 study; MD -0.30, 95% CI -2.23 to 1.63), scale (2 studies; MD -0.2, 95% CI -0.84 to 0.45, and visibility (1 study; MD -0.40, 95% CI -2.49 to 1.69).There was a significant difference in the area affected (2 studies; MD -0.59, 95% CI -1.13 to -0.06) in favour of fish oil. No significant difference was found for induration (1 study; MD 0.8, 95% CI -0.03 to 1.63) or pruritus (1 study; MD -0.2, 95% CI -1.03 to 0.63). Results for itch at the end of treatment, as rated by the participant, significantly favoured the fish oil group (1 study; MD -2.50, 95% CI -4.46 to -0.54).