The Full Story
There are two types of evergreen shrubs with the common name mistletoe: American mistletoe (Phoradendron serotinum) and European mistletoe (Viscum album). Abundant literature and folklore describe the European variety’s herbal, mythical, and medicinal history. Poisonings and deaths have been reported from ingestion of European mistletoe. American mistletoe’s toxic reputation is probably guilt by association because it has the same common name as its European relative.
How poisonous is ingestion of American mistletoe? One study examined the outcomes of 1754 American mistletoe exposures. The overwhelming majority of exposures occurred during the Christmas season when American mistletoe is used decoratively. Children accounted for 92% of these cases, and 96% of all exposures were by swallowing. The vast majority of patients had no symptoms and there were no fatalities, including the 72 people who swallowed mistletoe on purpose.
Another study described 92 American mistletoe exposures (mostly very young children) reported to three poison control centers. Ingestions of up to 20 berries and five leaves were reported. In cases where five or more berries were consumed, none of the patients had symptoms. Three of the 11 patients who swallowed 1-5 leaves developed gastrointestinal upset. One child had a seizure, but it could not be clearly connected to mistletoe. The study concluded that symptoms are uncommon even in large ingestions of American mistletoe.
It appears that American Phoradendron mistletoe is less toxic than the European species Viscum album. The literature on the European variety includes reports of serious poisonings and deaths, usually due to excessive concentrated herbal use such as brewing mistletoe in tea. V. album is not native to or sold in the US, but it could be privately imported.
American mistletoe doesn’t deserve its highly toxic reputation. According to ancient myth, anyone kissed under mistletoe would be blessed by love. So enjoy the “kissing ball” this holiday season but, as with any plant, keep it out of reach of curious children and pets!
If you think someone might have swallowed mistletoe, call Poison Control right away at 1-800-222-1222. If no symptoms are present yet, you can also get help using the webPOISONCONTROL® online tool.
Mary Elizabeth May, RN, BA, MPH
Certified Specialist in Poison Information
Courtemanche J, Peterson, RG. Beware the mistletoe. CMAJ. 2006;12:1523-4.
Evens ZN, Stellpflug SJ. Holiday plants with toxic misconceptions. West J Emerg Med. 2012;6:538-42.
Hall AH, Spoerke DG, Rumack BH. Assessing mistletoe toxicity. Ann Emerg Med.1986;11:1320-3.
Krenzelok EP, Jacobsen TD, Aronis J. American mistletoe exposures. Am J Emerg Med. 1997;15:516-20.
Spiller HA, Willias DB, Gorman SE, et al. Retrospective study of mistletoe ingestion. J Toxicol Clin Toxicol. 1996;34:405-8.
Waddell RK, 2nd. Holiday season safety. Adult supervision is pivotal for safe holidays. EMS Mag. 2007;36:141.