Effect of gentian violet, corticosteroid and tar preparations in Staphylococcus-aureus-colonized atopic eczema

Background: In atopic eczema (AE), skin colonization with Staphylococcus au reus plays a possible role in the pathophysiology of the disease. Methods: Thirty-eight patients with AE were screened for their cutaneous colonizatio n with S. aureus. The antibacterial and clinical efficacy of topical therap y with the antiseptic dye gentian violet, a potent glucocorticosteroid or a tar solution (liquor carbonis detergens) was evaluated in vivo in 21 patie nts with a density of >10(4) CFU/cm(2) and in vitro. Skin sites were treate d twice daily for 4 days with the active drug or a corresponding control. Q uantification of S. aureus was done daily during therapy as well as 3 days thereafter. The severity of the lesions was rated bk a regional SCORAD. Res ults: In gentian-violet-treated skin, bacterial density decreased significa ntly in lesional (p < 0.001) and unaffected skin (p < 0.001). Bacterial den sities did not decrease during therapy with glucocorticosteroid or liquor c arbonis detergens but dropped afterwards. All therapeutics reduced the seve rity score, reduction being greatest for the glucocorticosteroid and lowest for liquor carbonis detergens. In vitro, a high antibactericidal efficacy was demonstrated only for gentian violet. Conclusions: Antibacterial therap y with gentian violet not only reduces S. aureus dramatically, but also red uces the severity of the eczema. Reduction of S. aureus after therapy with glucocorticosteroids and LCD seems to be secondary to improvement of the sk in condition.