- Author: Jason F Kearney, MD, MBA; Chief Editor: Asim Tarabar, MD more...
Plant exposures are some of the most frequent poisonings reported to poison control centers. Exposures to plants containing oxalate crystals, such as Philodendron and Dieffenbachia, are among the most common toxic plant exposures reported in the US.
For the past 200 years, the irritant properties of the Dieffenbachia plant have had various uses, including punishing slaves and treating gout, impotence, and frigidity. Today, plants containing oxalate are admired for their ornamental beauty and found in public places and homes.
The following plants contain oxalates:
Anthurium ( Anthurium species)
Arum, Araceae ( Arisaema species)
Caladium ( Caladium bicolor)
Calla lily ( Zantedeschia species)
Chinese evergreen ( Aglaonema species)
Dieffenbachia ( Dieffenbachia species) (see the image below) 
Monstera, Ceriman ( Monstera deliciosa)
Nephthytis ( Syngonium podophyllum)
Philodendron ( Philodendron species)
Pothos or Hunter's robe ( Epipremnum aureum)
Nonsoluble calcium oxalate crystals are found in plant stems, roots, and leaves. The stalk of the Dieffenbachia plant produces the most severe reactions. These needlelike crystals produce pain and edema when they contact lips, tongue, oral mucosa, conjunctiva, or skin. Edema primarily is due to direct trauma from the needlelike crystals and, to a lesser extent, by other plant toxins (eg, bradykinins, enzymes).[3, 4]
Philodendron and Dieffenbachia exposures are among the most common plant exposures reported to poison control centers.
According to the 2009 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS), 6,803 single exposures were documented for oxalate plant poisonings.
In most cases, nonsoluble oxalate plants produce self-limited symptoms and clinical manifestations. Significant morbidity or mortality is extremely rare. One case report of an infant fatality attributed to airway obstruction after exposure to Dieffenbachia exists.
The 2007 Annual Report of the American Association of Poison Control Centers' NPDS reported 1145 minor outcomes, 81 moderate outcomes, 3 major outcomes, and no deaths from oxalate plant exposures.
The majority of oxalate plant exposures occur in children younger than 5 years while sampling houseplants in the home.
The 2007 Annual Report of the American Association of Poison Control Centers' NPDS reported 6020 oxalate plant exposures in those younger than 6 years, 762 exposures in those aged 6-19 years, and 455 exposures in those older than 19 years.
Wang B, Han L, Chen C, Wang Z. The complete chloroplast genome sequence of Dieffenbachia seguine (Araceae). Mitochondrial DNA. 2015 Jul 8. 65 (4):1-2. [Medline].
Gardner DG. Injury to the oral mucous membranes caused by the common houseplant, dieffenbachia. A review. Oral Surg Oral Med Oral Pathol. 1994 Nov. 78(5):631-3. [Medline].
Lin TJ, Hung DZ, Hu WH, Yang DY, Wu TC, Deng JF. Calcium oxalate is the main toxic component in clinical presentations of alocasis macrorrhiza (L) Schott and Endl poisonings. Vet Hum Toxicol. 1998 Apr. 40(2):93-5. [Medline].
Zhong LY, Wu H. [Current researching situation of mucosal irritant compontents in Araceae family plants]. Zhongguo Zhong Yao Za Zhi. 2006 Sep. 31(18):1561-3. [Medline].
Bronstein AC, Spyker DA, Cantilena LR Jr, Green JL, Rumack BH, Giffin SL. 2009 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 27th Annual Report. Clin Toxicol (Phila). 2010 Dec. 48(10):979-1178. [Medline].
Fochtman FW, Manno JE, Winek CL, Cooper JA. Toxicity of the genus Dieffenbachia. Toxicol Appl Pharmacol. 1969 Jul. 15:38-45. [Medline].
Jaspersen-Schib R, Theus L, Guirguis-Oeschger M, Gossweiler B, Meier-Abt PJ. [Serious plant poisonings in Switzerland 1966-1994. Case analysis from the Swiss Toxicology Information Center]. Schweiz Med Wochenschr. 1996 Jun 22. 126(25):1085-98. [Medline].
Krenzelok EP, Jacobsen TD, Aronis JM. Plant exposures: a state profile of the most common species. Vet Hum Toxicol. 1996 Aug. 38(4):289-98. [Medline].
Lampe KF. AMA Handbook of Poisonous and Injurious Plants. AMA; 1985. 1-6, 72.
Loretti AP, da Silva Ilha MR, Ribeiro RE. Accidental fatal poisoning of a dog by Dieffenbachia picta (dumb cane). Vet Hum Toxicol. 2003 Oct. 45(5):233-9. [Medline].
Manríquez O, Varas J, Ríos JC, Concha F, Paris E. Analysis of 156 cases of plant intoxication received in the Toxicologic Information Center at Catholic University of Chile. Vet Hum Toxicol. 2002 Feb. 44(1):31-2. [Medline].
McIntire MS, Guest JR, Porterfield JF. Philodendron--an infant death. J Toxicol Clin Toxicol. 1990. 28(2):177-83. [Medline].
Mitchell JC, Rook A. Botanical Dermatology: Plants and Plant Products. 1979. 114-5.
Mrvos R, Dean BS, Krenzelok EP. Philodendron/dieffenbachia ingestions: are they a problem?. J Toxicol Clin Toxicol. 1991. 29(4):485-91. [Medline].
Ogzewalla CD, Bonfiglio JF, Sigell LT. Common plants and their toxicity. Pediatr Clin North Am. 1987 Dec. 34(6):1557-98. [Medline].
Pamies RJ, Powell R, Herold AH, Martinez J III. The dieffenbachia plant. Case history. J Fla Med Assoc. 1992 Nov. 79(11):760-1. [Medline].
Rauber A. Observations on the idioblasts of Dieffenbachia. J Toxicol Clin Toxicol. 1985. 23(2-3):79-90. [Medline].
Tagwireyi D, Ball DE. The management of Elephant's Ear poisoning. Hum Exp Toxicol. 2001 Apr. 20(4):189-92. [Medline].
Watson JT, Jones RC, Siston AM, Diaz PS, Gerber SI, Crowe JB. Outbreak of food-borne illness associated with plant material containing raphides. Clin Toxicol (Phila). 2005. 43(1):17-21. [Medline].