Mistletoe, a plant often associated with holiday tradition and romance, is toxic to humans. The severity of poisoning is highly dependent on the particular species ingested and the quantity consumed. Understanding the distinction between the varieties and the compounds they contain is necessary for assessing the true danger of accidental exposure.
Differentiating Mistletoe Species and General Risk
The toxicity of mistletoe varies based on its geographical origin, corresponding to two primary species. The American mistletoe (Phoradendron serotinum or Phoradendron leucarpum) is common in North America and is generally considered the less toxic variety. Ingesting small amounts usually results in mild gastrointestinal upset, with serious complications being extremely rare.
The European mistletoe (Viscum album) is found throughout Europe and western Asia and poses a greater risk. This species contains higher concentrations of potent toxic compounds, and historical reports link it to more severe poisoning incidents. The risk is elevated for young children who may be exposed to the plant during the winter holiday season.
Toxic Compounds and Ingestion Symptoms
The poisonous nature of mistletoe stems from biologically active proteins and peptides concentrated within the plant’s leaves and berries. In the American variety, the primary toxic agents are phoratoxins. These proteins act by disrupting cell membranes, though this effect is usually confined to the lining of the digestive tract after mild ingestion.
European mistletoe contains a more potent class of toxins, including viscotoxins and viscumin, which are highly toxic ribosome-inactivating proteins. Viscumin inhibits the process of protein synthesis within cells. This mechanism can lead to cell death, particularly in tissues with a high cellular turnover rate, such as the gastrointestinal tract.
Common symptoms of mild mistletoe ingestion, regardless of the species, include nausea, vomiting, diarrhea, and abdominal cramping. In rare cases involving large quantities of the European species or highly concentrated preparations, severe systemic effects can manifest. These serious effects can include a slow heart rate (bradycardia), low blood pressure, central nervous system damage leading to delirium, and damage to the kidneys or liver.
Immediate Action and Medical Response
If mistletoe ingestion is suspected, immediate action is necessary to ensure safety, regardless of the quantity consumed or the species involved. The first step is to contact the national Poison Control Center at 1-800-222-1222 in the United States. This resource provides expert guidance based on the specifics of the exposure.
Before calling, gather specific details:
- The patient’s age and weight.
- The approximate amount of plant material consumed.
- The time of ingestion.
- The part of the plant that was eaten, such as berries or leaves.
Medical professionals use this information to determine the level of risk and the appropriate course of action.
In a healthcare setting, the treatment for mistletoe poisoning is primarily supportive, meaning there is no specific antidote. The medical team focuses on monitoring the patient’s vital signs, such as heart rate and breathing, to detect systemic toxicity. Treatment may involve administering intravenous fluids to manage dehydration and managing any specific symptoms that arise.