Effect of antimicrobial soap containing chlorhexidine on the microbial flora of skin.

The qualitative and semiquantitative changes in the aerobic microbial flora of normal skin with the prolonged use of a chlorhexidine scrub (6 months) were investigated. More samples in the chlorhexidine scrub group had gram-negative bacilli in their axilla (63 of 96, 66%) and groin (36 of 96, 38%) than the controls (32 of 66, 49%, for axilla and 7 of 66, 11%, for groin; P = 0.01). Klebsiella and Enterobacter were the predominant organisms in the control and chlorhexidine groups, respectively. The chlorhexidine scrub produced a reduction in the total aerobic counts in the axilla, groin, and between the toes and the fingers. Fewer samples from the chlorhexidine-treated areas revealed the presence of lipophilic diphtheroids than did the controls. Lipophilic diphteroids were also reduced quantitatively in the groin and axilla with chlorhexidine treatment. No consistent pattern for the other major groups of bacteria was noted between the treatments.