Abstract: Objective To investigate the colonization features of Staphylococcus aureus (S. aureus) in the skin lesions of eczema and atopic dermatitis (AD), and to evaluate the therapeutic effect of combination topical treatment with mupirocin and hydrocortisone butyrate. Methods A multicentre, double-blind randomized trial was conducted. The SCORAD was evaluated on day 1, 7, 14 and 28. Swabs for bacterial isolation were taken from the lesional skin and non-lesional skin. A combination topical therapy with mupirocin ointment and hydrocortisone butyrate ointment was used in treatment group, with vehicle ointment and hydrocortisone butyrate ointment as a control. Results Three hundred and twenty seven patients were enrolled in the study, including 208 patients with eczema and 119 patients with atopic dermatitis. Bacteria were isolated from 70.19% of lesional skin and 32.69% of non-lesional skin of patients with eczema, in which S. aureus accounted for 47.26% and 27.94% respectively. Bacteria were isolated from 74.79% of the lesional skin and 34.45% of non-lesional skin of patients with atopic dermatitis, in which S. aureus accounted and 79.78% or 80.49% respectively. The amount of S. aureus colonized was markedly higher in the lesional skin than that in non-lesional skin, either in eczema patients or in atopic dermatitis (P<0.01, P<0.05), which was positively correlated with the severity of the lesion. There was no difference in the gross therapeutic effect between combination therapy group and control group after treatment. However, in the eczema patients with clinical score more than 8 or in the AD patients with clinical score more than 7, the therapeutic effect of the combination therapy group was superior to that in the control group (P<0.05) seven days after theatment. There were no differences between the two groups 14 days and 28 days after treatment (P>0.05). Conclusions The bacterial colonization, especially S. aureus, is more frequently dectected in the lesional skin of eczema patients and AD patients than that in the non-lesional skin, which may be related in the pathogenesis of eczema and AD. And, early application of combination therapy with topical antibiotics and corticosteroids is beneficial to the patients.

Key words: Eczema, Dermatitis, atopic, Staphylococcus aureus, Controlled clinical trials