Efficacy of topical beta-blockers in the management of EGFR-inhibitor induced paronychia and pyogenic granuloma-like lesions: case series and review of the literature.

Nail toxicities, such as paronychia and pyogenic granuloma-like lesions, are well-recognized side effects of epidermal growth factor receptor inhibitor (EGFR-I) therapy that can significantly impair patient's quality of life and compliance to anticancer treatment. Numerous therapeutic options are available, with variable rates of success. Recently, topical β-blockers have emerged as a novel, non-invasive treatment strategy. We tested the effectiveness of topical timolol 0.5% gel, twice daily, under occlusion for 30 days, on paronychia and periungual pyogenic granuloma-like lesions in 9 patients being treated with EGFR-I. We also reviewed the available literature on this topic, which is the use of topical β-blockers in the management of EGFR-I-induced nail toxicities. We assessed 25 lesions consistent with the diagnosis of EGFR-I-induced pyogenic granuloma-like lesions and paronychia (21 diagnosed as pyogenic granuloma-like, and four as paronychia). Thirteen of the 25 lesions achieved complete resolution, 9/25 reached at least improvement, and only 3/25 did not respond to the intervention. As for the review, four papers met the scope of our research. The results confirmed at least partial benefit in the majority of treated patients. Among current strategies, high-potency topical corticosteroids are a well-known treatment option especially for paronychia, targeting the inflammatory component of such lesions; nevertheless, the management of pyogenic granuloma-like lesion is often more complex and the success rate is variable. Nail plate avulsion and phenol chemical matricectomy are not highly effective and display some degree of invasiveness. Topical β-blockers seem to be promising alternatives, especially in fragile cancer patients who may be unsuitable candidates for an invasive procedure.