Alocasia odora poisoning due to calcium oxalate needle crystals in Japan.

Objective: To elucidate the actual circumstances of damage caused by Japanese Alocasia (A) odora. Materials and Methods: We investigated cases in Japan from our own hospital in the eastern part of Shizuoka Prefecture as well as published reports. Results: A. dorais found in western Japan, and plants of the Alocasia genus are cultivated often. A. odora is frequently associated with food poisoning because its aboveground parts resemble those of Satoimo (Colocasia esculenta). Moreover, A. odora contains insoluble calcium oxalate crystals, which cause poisoning symptoms, such as oral pain, nausea, vomiting, and laryngeal edema, resulting in near asphyxia, diarrhea following shock, and skin dermatitis. Calcium oxalate crystals are abundant in Araceae family plants, and cases of health damage owing to the accidental ingestion of Araceae plants have been reported worldwide. Conclusion: Due to the strong irritation felt in the mouth upon contact with the plant, it is advisable to immediately spit out the plant and rinse the mouth. In addition to drug administration, ensuring a secure airway may be necessary if there is a risk of asphyxiation.