Pseudomembranous Conjunctivitis following Exposure to Arisaema ringens Sap: A Case Report

Plants of the Araceae family exude a sap containing calcium oxalate, a toxic substance that causes dermatitis. However, ocular injury due to exposure to Araceae sap has rarely been reported. Herein, we present a case of severe pseudomembranous conjunctivitis following exposure to Arisaema ringens, an Araceae species and popular houseplant in Japan. A 67-year-old man presented with pain in his right eye after exposure to the sap of A. ringens. At presentation, the best corrected visual acuity and intraocular pressure in the right eye were 20/800 and 15 mm Hg. Slit-lamp examination showed strong hyperemia, conjunctival chemosis, and corneal edema with many pseudomembranes, and fluorescein staining revealed corneal epithelial defects in the central area of the cornea. We washed the ocular surface with saline and initiated treatment with topical instillations of 1.5% levofloxacin and 0.1% betamethasone, combined with ofloxacin eye ointment. After repeatedly removing the pseudomembranes and increasing the frequency of the topical instillations, pseudomembranous conjunctivitis and corneal erosion gradually improved. One week following the injury, the corneal epithelial defects were no longer detectable, and the patient's best corrected visual acuity recovered to 20/25. It is important for ophthalmologists and primary care physicians to be aware of the ocular toxicity of A. ringens and should counsel their patients accordingly. Moreover, preventative measures, such as the use of protective eyewear, should be taken when cutting this houseplant.