Are topical beta-blockers really effective "in real life" for targeted therapy-induced paronychia.

Paronychia and periungual pyogenic granuloma represent one of the most common and bothersome dermatologic toxicities observed with ErbB inhibitors. There is no standardized treatment, and management remains challenging. Moreover, conservative management with noninvasive treatment should be promoted for fragile patients in a metastatic setting. Over the last few years, the efficacy of topical blocking agents has been considered for managing cutaneous or mucosal pyogenic granulomas. Very recently, the use of topical propranolol or of timolol has been reported in several patients undergoing treatment with EGFR inhibitors and developing pyogenic granulomas of the nail. We performed a retrospective single-center review of patients with targeted therapy-related paronychia/periungual pyogenic granulomas who had been treated with topical timolol, either alone or in combination with other topical treatments. Nearly two thirds of patients showed at least a partial response after 1 month of therapy, and the use of a topical beta-blocker in our population was associated with a favorable safety profile. Finally, topical timolol may represent a promising treatment option for the management of cancer patients suffering from painful periungual lesions. Comparative clinical trials, however, are still needed.