Ibrutinib-Induced Paronychia and Periungual Pyogenic Granuloma.

Nail changes elicited by Ibrutinib are relatively infrequent but are reported in the literature. Herein, we report on two cases that developed Ibrutinib-induced nail toxicities. A 63-year-old female, with relapsing mantle cell lymphoma on Ibrutinib 560mg/day for seven months developed paronychia, onychomadesis, Beau's lines, nail fragility, and brittleness over fingernails and toenails. On the other hand, an 80-year-old male with chronic lymphoid leukemia developed a bloody papule with hemorrhagic crust and nail-plate abnormalities. Skin toxicities manifested eight months after initiating Ibrutinib therapy. From a clinical perspective, Ibrutinib-induced chronic paronychia and PG have been established. All other PG triggers have been ruled out. After the cessation of Ibrutinib, the PG improved for both cases. The exact pathogenesis of PG induced by Ibrutinib is not yet understood but it had been compared to retinoid-related changes. Thus, further research and reporting of similar cases should be done to further understand the pathophysiology of such manifestations.