CHANGES IN STAPHYLOCOCCUS-AUREUS DENSITY AND LESION SEVERITY AFTER TOPICAL APPLICATION OF POVIDONE-IODINE IN CASES OF ATOPIC-DERMATITIS

A case-control study was performed to examine the efficacy of 10% povi done-iodine solution applied to atopic dermatitis patients. The densit y of Staphylococcus aureus on the eczematous lesions and the lesion se verity before and after the topical application of povidone-iodine wer e compared. We found a 10-100-fold decrease in the density of S. aureu s after povidone-iodine treatment in patients colonizing S. aureus at an initial density of > 1000 CFU/10 cm(2). Erythema and exudation also decreased after povidone-iodine treatment in patients colonizing S. a ureus at an initial density of > 1000 CFU/10 cm(2). The 10% povidone-i odine solution disinfected S. aureus cells when added immediately afte r the cells were mixed in human plasma; however, 10% povidone-iodine s olution only reduced the density of S. aureus cells by 10-100-fold whe n S. aureus cells were harvested after a 24 h incubation in human plas ma. Staphylococcus aureus cells harvested after 24 h incubation in hum an plasma were often surrounded by fibrin bundles and cells circumscri bed by fibrin bundles could not be disinfected with 10% povidone-iodin e solution. We suggest that S. aureus cells may produce biofilm-like s tructures in atopic dermatitis patients and that these structures may help S. aureus cells resist the 10% povidone-iodine treatment. (C) 199 7 Elsevier Science Ireland Ltd.