The correct answer is D. Topical corticosteroid.
The patient’s lesions are most consistent with a Grover disease-like eruption related to a BRAF inhibitor for metastatic melanoma. For this eruption, the most appropriate treatment is a topical corticosteroid.
Dupilumab may be considered if the eruption is related to atopic dermatitis; however, these lesions are not eczematous in nature. Etanercept may be used for psoriatic lesions, but these lesions are more consistent with a Grover disease-like eruption. Oral terbinafine and topical ketoconazole may be used for a fungal infection, though this is less likely in the given scenario.
Carlos G, Anforth R, Clements A, et al. Cutaneous Toxic Effects of BRAF Inhibitors Alone and in Combination With MEK Inhibitors for Metastatic Melanoma. JAMA Dermatol. 2015;151(10):1103-1109.