What kind of rash is it?: deciphering the dermatologic toxicities of biologic and targeted therapies.

: An overwhelming number of new agents, including targeted agents with unique mechanisms of action, are available in oncology practice today. Along with the benefit of new treatments for patients comes the unfamiliarity of associated toxicities and learning the best methods to minimize side effects. One such toxicity has been the spectrum of dermatologic reactions from some of the newer small-molecule inhibitors and monoclonal antibodies. Scientific evidence describing the unique rashes and methodologies to treat various cutaneous toxicities with specific agents is extremely limited. This article reviews the currently available literature related to dermatologic toxicities observed with many newer targeted therapies. Current recommendations for management are based on practices implemented during clinical trials and postmarketing practices. Additional research is needed to further elucidate the most efficacious methods for treating side effects observed with newer targeted therapies.