A Case of Transient Eruptive Keratoacanthoma Associated With Nivolumab

Anti-PD-1 immunotherapy agents are known to cause cutaneous side effects in up to 42% of patients with melanoma, infrequently including eruptive keratoacanthomas (de Golian et al., 2016, p. 57). Although traditionally documented with pembrolizumab use, increasing reports of eruptive keratoacanthomas with nivolumab use are emerging in the literature (Bednarek et al., 2018, pp. e28-e29). We present a similar case of a 74-year-old woman with melanoma of the right upper extremity with metastases to the lung. She received her first infusion of nivolumab and, within 2 weeks, developed a pruritic rash on the right arm. Within 1 month, the rash spread to all extremities and would blister, scale, and slough off. Punch biopsy of the right lower extremity revealed squamous proliferation suspicious for eruptive keratoacanthoma secondary to nivolumab therapy. The patient continued nivolumab and was referred to dermatology to monitor.