The dermatoscope: a potential source of nosocomial infection?

Dermatoscopes are directly placed on the skin of patients and therefore may harbour potentially pathogenic bacteria. In this study we assessed bacterial contamination of dermatoscopes during routine use and examined the effectiveness of isopropyl alcohol and disposable lens covers. Aerobic bacterial cultures were performed on randomly selected dermatoscopes after examination of 39 patients. In addition, bacterial contamination of dermatoscopes after cleaning with 70% isopropyl alcohol and after using a disposable transparent lens cover was tested. Bacteria such as Staphylococcus epidermidis, Micrococcus species and Corynebacterium species, which are usually present on the skin, were repeatedly identified. In addition, rare bacteria such as Moraxella species were found. Known nosocomial micro-organisms such as Staphylococcus aureus were recovered from hospitalized patients. Disinfection with 70% isopropyl alcohol and the use of a disposable lens cover significantly reduced the number of bacteria. Image quality was identical with and without the use of a transparent lens cover. Dermatoscopes harbour potential pathogens and may be a source of bacterial transmission. Isopropyl alcohol is an effective cleaning agent for dermatoscopes. Disposable lens covers completely prevented bacterial transmission and are therefore recommended for routine dermatoscopy, especially in hospitalized patients.