Recalcitrant trametinib-induced paronychia treated successfully with topical timolol in a pediatric patient.

Paronychia has been described as a side effect in patients undergoing treatment with MEK (mitogen activated protein kinase enzyme) inhibitors. It is usually a recurrent condition that can have a significant impact in the quality of life. Topical beta blocker treatment has been described as an effective therapy in antineoplastic-induced pyogenic granulomas and in antineoplastic-induced paronychia. We describe the first case treated with topical timolol for a trametinib-induced paronychia in a pediatric patient that allowed to continue the third line antineoplastic therapy for his glioma.