Rapidly progressive streptococcus dysgalactiae corneal ulceration associated with erlotinib use in stage IV lung cancer

PURPOSE: To present a unique case of streptococcus dysgalactiae keratitis with progression to corneal perforation and endophthalmitis, in the setting of epidermal growth factor receptor inhibitor (erlotinib) therapy for advanced non-small cell lung cancer. OBSERVATIONS: An 89-year-old female with non-small cell lung cancer on erlotinib presented with corneal perforation due to infectious keratitis. Microbial cultures grew streptococcus dysgalactiae, a virulent pathogen known to affect immunocompromised patients that has not been previously described to cause infectious keratitis. Despite aggressive medical intervention, the clinical course was complicated by rapid progression to no light perception visual acuity in the setting of endophthalmitis with orbital cellulitis, necessitating evisceration. CONCLUSIONS AND IMPORTANCE: Epidermal growth factor receptor inhibitor therapy can result in significant ocular complications including dry eyes, epithelial keratopathy, non-healing abrasions, infectious keratitis, and rarely, corneal melting and perforation. These side effects can predispose patients to aggressive infections with rare organisms, highlighting the importance of understanding the ocular side effects of systemic chemotherapeutic agents.