Elephant ear poisoning

The harmful substances in elephant ear plants are:

• Oxalic acid
• Asparagine, an amino acid found in this plant

Note: Leaves and stems are the most dangerous when eaten in large amounts.

Elephant ear grows naturally in tropical and subtropical areas. It is also common in northern climates.

Symptoms of elephant ear poisoning are:

• Blisters in the mouth
• Burning in mouth and throat
• Increased saliva production
• Pain when swallowing
• Hoarse voice
• Diarrhea
• Nausea and vomiting
• Redness, pain, and burning of the eyes
• Swelling of the tongue, mouth, and eyes

Blistering and swelling in the mouth may be severe enough to prevent normal speaking and swallowing.

Wipe out the mouth with a cold, wet cloth. Wash off any plant sap on the skin. Rinse out the eyes.

Do not make the person throw up unless poison control or a health care provider tells you to.

Have this information ready:

• Person's age, weight, and condition
• Part of plant swallowed, if known
• Time swallowed
• Amount swallowed

The local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

You can also get online poison help now at Poisonhelp.org. Just enter the product, poison, or medicine to get expert help.

Take the plant with you to the hospital, if possible.

The provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated as appropriate. Corneal damage will require additional treatment, possibly from an eye specialist.

Tests that may be done include:

• Blood and urine tests

Treatment may include:

• Breathing support, including tube through the mouth into the lungs and connected to a breathing machine (ventilator).
• Fluids through a vein (by IV)
• Medicine to treat the effects of the poison and other symptoms

If contact with the person's mouth is not severe, symptoms usually resolve within a few days. For people who do have severe contact with the plant, a longer recovery time may be necessary.

In rare cases, oxalic acid causes swelling severe enough to block the airways.

Do not touch or eat any plant that you are not familiar with. Wash your hands thoroughly after working in the garden or walking in the woods.

Auerbach PS, Constance BB, Freer L. Toxic plants. In: Auerbach PS, Constance BB, Freer L, eds. Field Guide to Wilderness Medicine. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 40.

Graeme KA. Toxic plant ingestions. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 65.

Higgins T. Wild plant and mushroom poisoning. In: Higgins T, ed. Medicine for the Outdoors. 7th ed. Philadelphia, PA: Elsevier; 2024:422-430.

Meehan TJ. Care of the poisoned patient. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 135.

Nelson LS, Calello DP. Acute poisoning. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 96.

Theobald JL, Corcoran JN. Poisoning. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 94.

Updated by: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.