Staphylococcus colonization in atopic dermatitis treated with fluticasone or tacrolimus with or without antibiotics

Background: The skin of patients with atopic dermatitis (AD) exhibits a striking susceptibility to colonization and infection by Staphylococcus aureus. Treatment with topical anti-inflammatory drugs alone can reduce S aureus colonization. Objectives: To compare the clinical severity of AD and the S aureus colonization rate between AD patients treated with topical glucocorticoids and those treated with tacrolimus and to evaluate the effects of complementary topical anti staphylococcal antibiotic therapy and the development of fusidic acid-resistant S aureus. Methods: Sixty AD patients were enrolled in a prospective, parallel, randomized study of an 8-week treatment with topical 0.05% fluticasone propionate or 0.03% tacrolimus, with or without complementary fusidic acid. Disease severity scoring of AD based on SCORing of Atopic Dermatitis (SCORAD), colonization rate and density of S aureus on the skin, and antibiotic susceptibility of S aureus isolates were evaluated. Results: The reduction in SCORAD scores correlated with the reduction of S aureus numbers. Treatment with topical tacrolimus resulted in a comparable reduction in SCORAD scores to fluticasone but a slower eradication of S aureus. Complementary fusidic acid had no additional benefit compared with fluticasone or tacrolimus alone. Two patients developed fusidic acid-resistant S aureus after 8 weeks of fusidic acid treatment. Conclusion: Tacrolimus is an appropriate alternative treatment for chronic AD. Topical anti-inflammatory therapy alone to improve the allergic skin inflammation of AD can reduce S aureus colonization of the skin. Topical antibiotics should be reserved for short-term use in obvious secondary bacterial infection.