Q: What are the different types of hand sanitizers? Which is the best one for the dermatologist to use in the office?
A: There are three categories of hand sanitizers in the current marketplace: alcohols, quaternary ammonium compounds and triclosan. The alcohol-based products contain ethanol, which has excellent killing against gram positive, gram negative, and fungal organisms. It should be recognized that ethanol does not kill bacterial spores and some enveloped viruses. Ethanol functions to denature proteins in infectious organisms and no resistance to this type of hand sanitizer have been identified.
The second type of hand sanitizer is based on quaternary ammonium compounds, such as benzaklonium chloride or benzethonium chloride. While the ethanol-based hand sanitizers are flammable, the quaternary ammonium compounds are not and can be used around hyfercator or electrocautery devices where a spark may be generated. Quaternary ammonium compounds fungistatic, bacteriostatic against gram-positive bacteria, and bacteriostatic against some gram negative bacteria. Like ethanol, the quaternary ammonium compounds are not active against nonenveloped viruses.
Some species of Staphylococcus aureus carry a gene that allows resistance to quaternary ammounium compounds. These organisms are also more likely to be antibiotic resistant, as well. Quarternary ammonium compound hand sanitizers may not be the best choice where methicillin resistant Staphylococcus aureus (MRSA) is a concern. Quaternary ammonium compounds adsorb to the cytoplasmic membrane of microbes causing leakage of cytoplasmic contents.
The third type of hand sanitizers contains triclosan. Triclosan is a commonly used antibacterial in a wide variety of products including deodorant soaps, toothpastes and mouth washes. Triclosan kills organisms by damaging the cell membrane, but has weak activity against gram-negative bacteria, such as Pseudomonas.
With all of this background, I would say that in general the ethanol based hand sanitizers are the most practical for the dermatologist to use on a daily basis. The chance of organism resistance to ethanol based hand sanitizers is the lowest and they are very cost effective. The main problem is their tremendous drying effect on the skin resulting in hand dermatitis. This is a secondary problem that the dermatologist must treat both personally and in patients!