Topical treatment of atopic dermatitis with St. John's wort cream--a randomized, placebo controlled, double blind half-side comparison.

BACKGROUND Recent investigations suggest an anti-inflammatory and antibacterial effect of hyperforin, which is a major constituent of Hypericum perforatum L. (Saint John's wort). OBJECTIVE In the present half-side comparison study we assessed the efficacy of a cream containing Hypericum: extract standardised to 1.5% hyperforin (verum) in comparison to the corresponding vehicle (placebo) for the treatment of subacute Atopic Dermatitis. The study design was a prospective randomised placebo-controlled double-blind monocentric study. METHODS In twenty one patients suffering from mild to moderate Atopic Dermatitis (mean SCORAD 44.5) the treatment with verum or placebo was randomly allocated to the left or right site of the body, respectively. The patients were treated twice daily over a period of four weeks. Eighteen patients completed the study. The severity of the skin lesions on the left and right site was determined by means of a modified SCORAD-index (primary endpoint). RESULTS The intensity of the eczematous lesions improved on both sites of treatment. However, the hypericum-cream was significantly superior to the vehicle at all clinical visits (days 7, 14, 28) (p < 0.05). Skin colonisation with Staphylococcus aureus was reduced by both verum and placebo, showing a trend to better antibacterial activity of the hypericum-cream (p = 0.064). Skin tolerance and cosmetic acceptability was good or excellent with both the hypericum-cream and the vehicle (secondary endpoints). CONCLUSION Taken together, the present study shows a significant superiority of the hypericum-cream compared to the vehicle in the topical treatment of mild to moderate Atopic Dermatitis. The therapeutic efficacy of the hypericum-cream, however, has to be evaluated in further studies with larger patient cohorts, in comparison to therapeutic standards (i.e. glucocorticoids).