Epistaxis secondary to panitumumab in a patient with colon cancer

Epidermal growth factor receptor inhibitors (EGFRIs) have become an integral part of therapy for many types of solid malignancy, including colorectal cancer. The drug class has proven to be effective without causing many of the side-effects associated with chemotherapy or other growth factor receptor inhibitors. Epistaxis, a common side-effect of Vascular Endothelial Growth Factor inhibitors, is rarely noted with EGFRIs. We report on one patient, a 51-year-old man with metastatic colon cancer, who developed severe epistaxis with the use of panitumumab. We discuss the other reported cases of EGFRIs causing epistaxis and hypothesize on possible mechanisms by which this drug class might cause mucosal bleeding.