Erythema Multiforme-Like Eruption Induced After Immune Checkpoint Inhibitor and Target Therapy in a Patient with Malignant Melanoma – A Case Report

Introduction. Erythema multiforme is an acute polyetiological hypersensitivity reaction characterized by polymorphic rashes of the skin and the mucous membranes. The triggering factors for the disease might be viral and bacterial infections, tumors, autoimmune connective tissue diseases, drugs. Immune checkpoint inhibitors are used for the treatment of multiple oncological diseases but they often cause cutaneous immune-related adverse events. Pembrolizumab is a monoclonal antibody that blocks the programmed death 1 receptor and leads to T-cytotoxic lymphocyte activation. Vemurafenib is a BRAF inhibitor which is used for the treatment of metastatic melanomas positive for BRAF V600E mutation and blocks tumor cell proliferation. Both of these agents improve survival of melanoma patients, but the modified immune condition often results in severe side effects.

Case presentation. We report a case of a 77-year-old male patient who developed severe erythema multiforme-like emption associated with Vemurafenib target therapy and Pembrolizumab immunotherapy for metastatic malignant melanoma.

Conclusion. Immune checkpoint inhibitors and target therapy prolong the patient’s life, resulting in significantly improved patient survival but various immune related cutaneous adverse reactions like erythema multifonne-like eruption or even Stevens-Johnson syndrome and toxic epidermal necrolysis can occur. Dermatologists play an important role in evaluating and managing these cutaneous toxicities. Our case presentation emphasizes the role of physicians in the follow-up of patients with malignant melanoma who must carefully observe general and dermatological status during the melanoma management.