A flowering houseplant, a philodendron grows six feet long leaves in a broad spread. It is sold under the name of Philodendron selloum and is a well known houseplant. Poisoning can occur when someone ingests any part of the plant, due to poisonous calcium oxalate. Calcium oxalate occurs throughout the plant and can poison humans, pets, and livestock.
Some of the signs of a poisoning from ingesting philodendron parts include vomiting, swelling of the tongue and mouth, slurred speech, nausea, diarrhea, irritated skin, burning in the mouth and throat, and burning painful eyes.
Do not make the person throw up unless told to by poison control. Give milk or water unless they are vomiting, having convulsions, are at a decreased level of alertness. Wipe their mouth with a wet cold cloth and wipe off any parts of the skin that were exposed to the sap. When you call poison control or emergency personnel, try to know how much of the plant was ingested and the time that it was ingested. While at the emergency, doctors will monitor the vital signs and overall health of the patient, treating the symptoms as appropriate.
This type of poisoning may block airways due to severe swelling and can lead to breathing problems. Although rare, this is still a possibility. The quicker that you can get treatment, the better the prognosis of the patient. Outlook also depends on how much of the plant was consumed.
Source: A.D.A.M., Plantcare.com