Merkel cell carcinoma in a psoriasis patient on long-term ixekizumab therapy: A case report.

A 69-year-old male receiving ixekizumab for plaque psoriasis presented with violaceous dermal nodules in a sporotrichoid pattern on the right distal lower leg. Biopsy and imaging led to the diagnosis of stage IIIB Merkel cell carcinoma. Treatment with avelumab, chemotherapy, and radiotherapy led to partial remission, but 4 years later, he succumbed to the disease. Ixekizumab-associated immunosuppression may have contributed to Merkel cell carcinoma development, a tumor known to occur more frequently in immunocompromised individuals.