Euphorbia milii 鐵海棠

POISONOUS PARTS

Sap.⁴

TOXICITY

• Toxic Constituents

  Milliamines, euphorbol and euphorbin.^4–6

• Mechanism

  Milliamines, euphorbol and euphorbin present in the sap are irritants to skin and mucosal membranes.^4,5

• Poisoning Features

  Eye contact: severe pain, lacrimation, corneal abrasion, keratoconjunctivitis and even temporary blindness. Skin contact: irritant contact dermatitis, blistering. Ingestion: swelling of oral mucosa, nausea, vomiting, diarrhoea.^4,8,9

• Poisoning Events

  In the United Kingdom, an old lady developed severe pain, lacrimation and blurred vision shortly after accidental spillage of sap into the eye while trimming the plant. She developed lid oedema, conjunctival injection and further decrease in visual acuity 16 hours after exposure. She recovered in 2 weeks.⁹

CLINICAL MANAGEMENT

Supportive treatment. For skin or ocular exposure, affected area could be irrigated with water.^4,8

IDENTIFICATION FEATURES

Diffuse shrubs, somewhat climbing. Stems up to 1 m or longer, dark brown, obtusely angulate and with stout spines, spines 1–2 cm long. Leaves 1.5–5 × 0.8–1.8 cm, apex mucronulate. Cyathia in long-pedunculate dichotomous cymes, each cyathium closely subtended by 2 broadly ovate bright red bracts about 1.3 cm in diameter. Peduncles 4–7 cm long, pedicels 6–10 mm long.¹⁰

MEDICINAL USES

Uses in TCM—stem, leaves, roots and sap: disperse abscesses and remove toxin, resolve phlegm and expel pus, activate blood, induce diuresis; flowers: cool blood and stanch bleeding. Recommended dose: stem, leaves, roots and sap 9–15 g, 10–15 flowers.^2,11,12

LABORATORY ANALYSIS

Milliamines can be detected by LC-MS/MS.¹³