Dieffenbachia seguine 花葉萬年青

Araceae 天南星科

Dieffenbachia¹

彩葉萬年青、黛粉葉²

POISONOUS PARTS

Whole plant, especially the stems.³

TOXICITY

Toxic Constituents
Calcium oxalate raphides and dumbcain.^3–6
Toxic Dose
A small piece of the plant can be toxic.^3,7
Mechanism
The toxic mechanism of the poisonous plants in the Araceae family is not fully understood. Calcium oxalate raphides stored in specialised cells known as idioblasts are released when subjected to mechanical pressure such as ingestion and contact, causing tissue irritation and inflammation. Other toxic ingredients that are commonly found in the family, such as sapotoxins and cyanogenic glycosides, may also play a role.^3,8
Poisoning Features
Skin contact: itchiness, burning sensation, irritant contact dermatitis. Eye contact: severe pain, lacrimation, corneal abrasion and keratoconjunctivitis. Ingestion: severe pain, burning sensation and inflammation of the oral cavity, tongue, throat and oesophagus; it can also cause salivation, dysphagia, vomiting, diarrhoea, dysphonia and airway obstruction.^5,9
Poisoning Events
Cases of D. seguine poisoning have been reported worldwide. In the United States, a 69-year-old man misidentified the plant as “sugar cane” and bit the stem. He experienced severe oral pain and spat it out immediately. He developed dysphagia, salivation and glossitis. Despite emergency supportive therapy, he gradually developed increasing dyspnoea necessitating an emergent tracheostomy. Subsequently he fully recovered.^9–12

CLINICAL MANAGEMENT

Supportive treatment. Maintenance of airway by intubation or tracheostomy may be required for severe cases with airway compromise.^5,9

IDENTIFICATION FEATURES

Perennial herbs. Stems about 1 m high, 1.5–2.5 cm thick, internodes 2–4 cm long. Petioles sheathing below; leaf blades 15–30 × 7–12 cm, dark green on both surfaces, shiny, with irregular oblong, white or yellow-green patches between veins, lateral veins elevated abaxially. Peduncles short; spathes narrow, cuspidate. Berries orange-green.²