Diffuse hyperpigmented lichenoid drug eruption secondary to Enzalutamide

•Enzalutamide is a potent second-generation androgen receptor (AR) antagonist used to treat metastatic castration resistant prostate carcinoma (mCPRC) and metastatic hormone sensitive prostate carcinoma (mHSPC).•While there have been reports of cutaneous adverse outcomes with enzalutamide use, enzalutamide has the fewest reported cutaneous manifestations of any AR inhibitor.•This is the first reported case to our knowledge of an enzalutamide-induced lichenoid drug eruption.•Enzalutamide-induced lichenoid drug eruptions may be immune-mediated. Enzalutamide is a potent second-generation androgen receptor (AR) antagonist used to treat metastatic castration resistant prostate carcinoma (mCPRC) and metastatic hormone sensitive prostate carcinoma (mHSPC). Side effects of enzalutamide include headaches, fatigue, hot flashes, xerosis and pruritus. Enzalutamide, however, has the fewest reported cutaneous adverse outcomes of any AR inhibitor. We report, to our knowledge, the first clinical presentation of a lichenoid drug eruption secondary to enzalutamide treatment in a 55-year-old-male with mCPRC.