Comparison of normal resident flora on the face of medical students who use and who do not use cosmetics

Introduction: Normal flora of the skin plays a beneficial role in preventing the pathogenic organisms from colonizing the skin and causing infection. It is possible that the facial cosmetics may cause a change in the normal flora disrupting its protective function. Aim: To find out the effect of cosmetics, those that are applied on to the face on resident normal flora of the face. Materials and Methods: This was a cross-sectional study involving medical students aged 19 to 25 years, of whom 42 were regular cosmetic users and another 42 were non cosmetic users. Swabs were taken from the face of the subjects after a face wash with soap and water and eluted in 1 ml sterile peptone water. Tenfold dilutions of the sample were made and 100 μl of the diluted sample was spread over the surface of Trypticase soy agar, Mac Conkey’s agar and blood agar. The colonies were counted and also identified. Statistical evaluation was done by Chi square test using SPSS version 16. Results: We isolated Coagulase Negative Staphylococci (CoNS), Micrococcus spp. and methicillin sensitive S.aureus, non-fermenting oxidase negative gram negative bacilli and diphtheroids from both the groups. We found that most of the students who were regular cosmetic users 22 (52.38%) yielded negligent growth in comparison with non-cosmetic users (16, 38%). CoNS was less frequently isolated from regular cosmetic users 10 (23.8%) in comparison with those who do not use cosmetics 17 (40.47%). Conclusion: It is possible that regular use of cosmetics does reduce the normal flora but further studies with larger sample size are required to prove and confirm this finding.