Insect Repellents: An Updated Review for the Clinician.

Malaria, Zika virus, West Nile virus, Dengue fever, and Lyme disease are common causes of morbidity and mortality around the world. While arthropod bites may cause local inflammation and discomfort, a greater concern is the potential to develop deadly systemic infection. The use of insect repellents (IR) to prevent systemic infections constitutes a fundamental public health effort. Cost-effectiveness, availability, and high-efficacy against arthropod vectors are key characteristics of an ideal IR. Currently, numerous IRs are available on the market, with DEET (N,N-diethyl-3-methylbenzamide) being the most widely used. DEET has an excellent safety profile and remarkable protection against mosquitoes and various other arthropods. Other EPA-registered IR ingredients (permethrin, picaridin, IR3535, oil of lemon eucalyptus, oil of citronella, catnip oil, and 2-undecanone) are alternative IRs of great interest due to some having efficacies comparable to that of DEET. These alternative IRs possess low toxicity and favorable customer experiences in utilization (e.g., cosmetically pleasant, naturally occurring). This review summarizes currently available EPA-registered IRs: the origins, mechanisms of action, side effect profiles, and available formulations will be discussed. This review will enable the clinician to select the best IR option to meet patients' needs and provide the greatest protection from arthropod bites and sequelae.