Cutaneous Reactions in Pediatric Patients Treated with MEK Inhibitors: A Retrospective Single-Center Study

Introduction: Mitogen-activated extracellular signal-regulated kinase (MEK) inhibitors are in use for several indications for adults and children. Cutaneous toxicities are among the most common adverse effects. We aimed to describe the spectrum of cutaneous adverse events, its frequency, and severity in a cohort of pediatric patients. Methods: We reviewed all records of patients in our tertiary treatment center treated with MEK inhibitors between January 2016 and January 2023 for all indications. Results: Among 33 patients, 76% reported cutaneous adverse effects. The highest prevalence was in the group of patients treated with trametinib (90%), followed by the group treated with selumetinib (50%) and the group treated with a combination of trametinib and B-Raf proto-oncogene serine/threonine-protein kinase inhibitor (dabrafenib, 34%). Xerosis, dermatitis, paronychia, and hair heterochromia were most frequently reported. Severity was graded 1 or 2 for most adverse events, and 237 visits to the dermatology clinic related to these adverse events were recorded. Conclusions: Cutaneous adverse events are common in the pediatric population as in adults, but the clinical spectrum is different. Although considered mild, multiple dermatological consultations reflect the distress caused by these events. Dermatologists have a central role in the multidisciplinary care of pediatric patients receiving these agents.