Ingestion of plants is one of the top 10 causes of poisoning nationwide. Decorative plants are found in many homes, and home landscaped yards provide access to a variety of attractive and potentially toxic plants. Fortunately, serious poisoning from plants is rare in children because the quantity of plant material required to cause serious poisoning is greater than what a small child ingests. Serious toxicity or death from plant ingestion is usually a result of intentional use (eg, jimson weed), misuse (eg, various teas steeped from plants), or suicide attempts (eg, oleander).

Plants can be categorized by their potential toxicity. Table II-49 describes the effects of various plant toxins, and Table II-50 provides an alphabetical list of many potentially toxic plants and herbs.

1. Group 1 plants contain systemically active poisons that may cause serious intoxication (see Table II-49).
2. Group 2a plants contain insoluble calcium oxalate crystals that may cause burning pain and swelling of the mucous membranes. Many houseplants are found in this category.
3. Group 2b plants contain soluble oxalate salts (sodium or potassium) that can produce acute hypocalcemia, renal injury, and other organ damage secondary to precipitation of calcium oxalate crystals in various organs. Mucous membrane irritation is rare, making it possible to ingest sufficient quantities to cause systemic toxicity. Gastroenteritis may also occur (see also oxalic acid).
4. Group 3 plants contain various toxins that generally produce mild-to-moderate GI irritation after ingestion or dermatitis after skin contact.

The amount of toxin ingested is usually unknown. Concentrations of the toxic agent may vary depending on the plant part, the season, and soil conditions. In general, childhood ingestions of a single leaf or a few petals, even of Group 1 plants, results in little or no toxicity because of the small amount of toxin absorbed. Steeping the plant in hot water (eg, an “herbal” tea) may allow very large amounts of toxin to be absorbed.

Depends on the active toxic agent (see Table II-49), although even nontoxic plants can cause coughing, choking, or gagging if a large piece is swallowed.

1. Group 1. In most cases, vomiting, abdominal pain, and diarrhea occur within 60-90 minutes of a significant ingestion, but systemic symptoms may be delayed a few hours while toxins are activated in the gut (eg, cyanogenic glycosides) or distributed to tissues (eg, cardiac glycosides). With some toxins (eg, ricin), severe gastroenteritis may result in massive fluid and electrolyte loss and GI sloughing.
2. Group 2a. Insoluble calcium oxalate crystals cause immediate oral burning, pain, and stinging upon contact with mucous membranes. Swelling of the lips, tongue, and pharynx may occur. In rare cases, glottic edema may result in airway obstruction. Symptoms usually resolve within a few hours.
3. Group 2b. Soluble oxalates may be absorbed into the circulation, where they precipitate with calcium. Acute hypocalcemia and multiple-organ injury, including renal tubular necrosis, may result (see “Oxalic acid,”).
4. Group 3. Skin or mucous membrane irritation may occur, although it is less severe than with Group 2 plants. Vomiting and diarrhea are common but usually mild to moderate and self-limited. Fluid and electrolyte imbalances caused by severe gastroenteritis are rare.

Usually is based on a history of exposure and the presence of plant material in vomitus. Identification of the plant is often difficult. Because common names sometimes refer to more than one plant, it is preferable to confirm the botanical name. If in doubt about the plant identification, take a cutting of the plant (not just a leaf or a berry) to a local nursery, florist, or college botany department.

1. Specific levels. Serum toxin levels are not available for most plant toxins. In selected cases, laboratory analyses for therapeutic drugs may be used (eg, digoxin assay for oleander glycosides, cyanide level for cyanogenic glycosides).
2. Other useful laboratory studies include CBC, electrolytes, glucose, BUN, creatinine, total and ionized calcium (for oxalate-containing plants), and urinalysis. Oxalic acid, if present, can form crystals observed on microscopy. If hepatotoxicity is suspected, obtain liver aminotransferases and prothrombin time (PT/INR).

Most ingestions cause no symptoms or only mild gastroenteritis. Patients recover quickly with supportive care.

1. Emergency and supportive measures
   1. Maintain an open airway and assist ventilation if necessary (see airway). Administer supplemental oxygen.
   2. Treat coma, seizures, arrhythmias, and hypotension if they occur.
   3. Replace fluid losses caused by gastroenteritis with IV crystalloid solutions.
2. Specific drugs and antidotes. There are few effective antidotes. Refer to discussions elsewhere in Section II for further details.
3. Decontamination
   1. Group 1 and Group 2b plants. Administer activated charcoal orally if conditions are appropriate (see Table I-37,). Gastric lavage is not necessary after small-to-moderate ingestions if activated charcoal can be given promptly. Gastric lavage may not be effective in removing larger plant parts. whole-bowel irrigation may be considered if large amounts of a toxic plant or plant parts were ingested and the patient arrives soon after the ingestion.
   2. Group 2a and Group 3 plants
      1. Wash the affected areas with soap and water and give sips of water to drink.
      2. Administer ice cream, juice bars, pudding, or cold milk to soothe irritated oral mucous membranes after exposure to insoluble oxalate plants.
      3. Do not induce vomiting because of potential aggravation or irritant effects. Activated charcoal is not necessary.
4. Enhanced elimination. These procedures are generally not effective.