Denosumab-induced cutaneous hypersensitivity reaction with distinct clinical and histopathologic findings.

Cutaneous reactions from targeted biologics are increasingly common. We describe a case of a cutaneous lichenoid drug eruption from the RANK inhibitor denosumab and a previously unreported lymphohistiocytic reaction pattern. The clinical and histopathological details of this case will aid in recognition, diagnosis, and treatment of drug rashes from denosumab.