Chlorhexidine avoids skin bacteria recolonization more than triclosan.

BACKGROUND: We do not know whether differences exist between the residual effect of 2% chlorhexidine in 70% isopropyl alcohol when compared with 1% triclosan in 70% isopropyl alcohol.

METHODS: Using an analytic, longitudinal, controlled, and comparative experimental trial, with blinded measurements, we recruited healthy, adult volunteers from the University of Guanajuato who completed a stabilization phase of skin microbiota and had no history of skin allergies. Four 25-cm2 areas of the inner surface of the forearms were designated for study: unscrubbed control for establishing baseline bacterial counts, scrubbed control with tridistilled water, scrubbed with chlorhexidine, and scrubbed with triclosan. Quantitative cultures were taken of all the areas at 0, 3, and 24 hours, using agar plates with neutralizing agents.

RESULTS: A total of 135 healthy volunteers were tested. At 24 hours, the unscrubbed control counts were 288 CFU/cm2 , whereas the scrubbed control counts were 96 CFU/cm2 ; 24 CFU/cm2 for chlorhexidine and 96 CFU/cm2 for triclosan (Kruskal-Wallis χ2 H = 64.27; P <.001).

CONCLUSIONS: Chlorhexidine is the best antiseptic option when a prolonged antiseptic effect is needed; for instance, when implanting medical devices or performing surgical procedures.