Should we instruct patients to rub topical agents into skin? The evidence

Background: At least 15 factors influence the ability of compounds to penetrate the skin. Massage (rubbing) may be another factor that has gone relatively unrecognized. Method: PubMed, Google Scholar, and EMBASE databases were accessed online in March 2018 in search of studies measuring absorption through skin with and without rubbing or massage. Results: While some studies noted no difference in dermal absorption with regards to rubbing, others have demonstrated the opposite. In general, massage technique does indeed sometimes enhance dermal absorption. In addition to increase skin temperature and blood flow, rubbing likely modifies stratum corneum (SC) structure to enhance diffusion rates and increase retained penetrant amount within the skin. Conclusions: Understanding the mechanism of massage and its role in percutaneous penetration may help elucidate skin barrier function, dermal absorption, skin decontamination, and dermatotoxicology. To achieve such goals, an in vitro model that models in vivo behaviors must first be established. Subsequently, experiments with different penetrants, vehicles, massage time, and other variables may be considered.