Philodendrons can contain as much as 0.7% of oxalates in the form of calcium oxalate crystals as raphides. The risk of death, if even possible, is extremely low if ingested by an average adult, although its consumption is generally considered unhealthy. In general, the calcium oxalate crystals have a very mild effect on humans, and large quantities have to be consumed for symptoms to even appear. Possible symptoms include increased salivation, a sensation of burning of the mouth, swelling of the tongue, stomatitis, dysphagia, an inability to speak, and edema. Cases of mild dermatitis due to contact with the leaves have also been reported, with symptoms including vesiculation and erythema. The chemical derivatives of alkenyl resorcinol are believed to be responsible for the dermatitis in some people. Contact with philodendron oils or fluids with the eyes have also been known to result in conjunctivitis. Fatal poisonings are extremely rare; one case of an infant eating small quantities of a philodendron resulting in hospitalization and death has been reported. This one case study, however, was found to be inconsistent with the findings from a second study. In this study, 127 cases of children ingesting philodendrons were studied, and they found only one child showed symptoms; a 10-month-old had minor upper lip swelling when he chewed on a philodendron leaf. The study also found the symptoms could subside without treatment and that previously reported cases of severe complications were exaggerated. In a 1961 study, 72 cases of cat poisonings were examined, of which 37 resulted in the death of the cat. The symptoms of the poisoned cats included excitability, spasms, seizures, kidney failure, and encephalitis.