In Vivo Confocal Microscopic Analysis of Keratitis Induced by Anaphylaxis to Intravenous Metronidazole: A Case Report and Literature Review

Keratitis induced by type I hypersensitivity to metronidazole is rarely reported. In vivo confocal microscopy (IVCM) is a promising method for the investigation of corneal morphology under pathological conditions. The purpose of the present study was to investigate the IVCM features of keratitis associated with anaphylaxis to metronidazole and review the literature regarding IVCM application to study drug-related changes in the cornea. A 50-year-old woman with acute bilateral keratitis induced by anaphylaxis to intravenous metronidazole presented to the Department of Ophthalmology, the first affiliated hospital of Jilin University, Changchun, China in Jan 2018. She initially experienced photophobia, moderate conjunctival injection, and watery discharge after infusion of intravenous metronidazole. These symptoms gradually resolved one month after she was administered anti-allergic drugs. Corneal morphology related to anaphylaxis to metronidazole was investigated by IVCM before and after treatment. To our knowledge, this is the first reported case of IVCM images of keratitis associated with anaphylaxis to metronidazole. In vivo confocal microscopy can allow objective evaluation of treatment response through cellular changes in the cornea and could provide good-quantity images of ocular surface tissues for follow-up.