Skin Autoimmunity Secondary to Alemtuzumab in a Tertiary Care Spanish Hospital.

Background and Objectives: The most common adverse events (AEs) after alemtuzumab (ALZ) include adverse infusion reactions, infections, and autoimmune disorders. Skin AEs are common during infusion, but there are few reported cases of long-term skin autoimmune disease. Methods: A retrospective case series of patients developing long-term autoimmune skin disorders after ALZ administration in a tertiary care hospital. Results: Of 133 patients treated with ALZ, 8 patients (6.02%) developed 9 autoimmune cutaneous AEs, including 4 events of alopecia areata, 2 of vitiligo, 2 of chronic urticaria, and 1 of inflammatory atrichia. Three of them occurred between the first and the second infusion. Discussion: The lesions described are secondary to autoimmune disorders, probably related to immune dysregulation because of a differential lymphocyte repopulation after ALZ. Autoimmune cutaneous AEs may be frequent, and it would be recommended to monitor its appearance to treat them.