Treatment of Psoriasis After Initiation of Nivolumab Therapy for Metastatic Malignant Melanoma: An Ancient Drug Revisited

A 69-year-old male was initiated with nivolumab 3 mg/kg every two weeks for metastatic BRAF-negative melanoma of the back. The patient’s medical history was notable for arterial hypertension and dyslipidemia for which he has been medically treated. There was no personal or family history of psoriasis. One week after the fourth cycle of nivolumab, asymptomatic, sharply bordered, erythematous and scaly plaques were seen on the the anterolateral aspects of shins, dorsa of hands, feet, scalp, and trunk (Figure 1a). A skin biopsy revealed psoriasiform epidermal hyperplasia with prominent orthohyperkeratosis, and mounds of parakeratosis, containing neutrophils. The suprapapillary epidermis was thinned, and there were collections of neutrophils in the spinous layers which were consistent with psoriasis (Figure 1b, 1c). The patient had psoriasis area and severity index score of 12. He did not have psoriatic arthritis. The patient’s melanoma improved with nivolumab therapy but the skin lesions increased. As the patient was refractory to topical therapies, he was switched to acitretin but experienced severe side effects (hyperlipidemia), so therapy