Beau's lines in a patient treated with moxifloxacin for anaerobic pulmonary infection.

Onychotoxicity of fluoroquinolones is a rare event. Previously described cases of fluoroquinolone-related nail disorders were due to onychophototoxicity. This report presents a case of nail toxicity after treatment with moxifloxacin for anaerobic pulmonary infection, which has not been described previously. The appearance and circumstances of this nail disorder were consistent with the diagnosis of Beau's lines.