What are the side effects of caladium? A Guide to Its Toxicity

September 30, 2025 •

4 min read

According to the ASPCA, caladiums are toxic due to insoluble calcium oxalate crystals that can cause significant oral and gastrointestinal irritation. Understanding what are the side effects of caladium is crucial for households with pets and children to ensure safety.

Quick Summary

Caladium plants contain insoluble calcium oxalate crystals that cause severe pain and swelling upon contact or ingestion. Exposure leads to oral irritation, swelling, difficulty swallowing, and skin rashes in humans and animals.

Key Points

Toxic Component: Caladium contains insoluble calcium oxalate crystals in all parts, which cause immediate irritation and swelling upon contact.
Oral Symptoms: Ingestion leads to an intense burning sensation, swelling, blistering, and difficulty swallowing or speaking.
External Effects: Direct contact with the plant's sap can cause skin irritation, rashes, and eye pain or potential corneal damage.
Risk to Pets: Caladium is toxic to pets, causing oral pain, pawing at the mouth, drooling, vomiting, and decreased appetite.
Emergency Action: In case of ingestion, rinse the mouth with a cold cloth and give milk; contact poison control immediately.
Prevention is Key: Keep caladiums out of reach of children and pets, and wear gloves when handling to prevent accidental exposure.

The Hidden Danger: Calcium Oxalate Crystals

Caladiums, with their vibrant, heart-shaped leaves, are a popular choice for indoor and outdoor decoration. However, their beauty hides a significant danger. The primary toxic component in all parts of the plant—including the leaves, stems, roots, and tubers—is a substance known as calcium oxalate. When the plant is chewed, bitten, or otherwise damaged, it releases microscopic, needle-like calcium oxalate crystals called raphides. These tiny shards can embed themselves into the soft tissues of the mouth, throat, skin, or eyes, causing immediate pain, burning, and swelling.

The Mechanism of Poisoning

The mechanism is primarily mechanical. The sharp crystals physically penetrate the body's tissues, triggering a rapid inflammatory response. This direct irritation is compounded by other potential plant toxins, which can increase the severity of the reaction. While the toxicity of caladium is rarely fatal to humans, it can cause extreme discomfort and, in severe cases, dangerous complications. For smaller bodies, such as those of children or pets, the effects can be more pronounced.

Side Effects in Humans

Ingesting or coming into contact with a caladium plant can produce a range of distressing symptoms in humans. These effects are typically acute and localized to the area of contact.

Oral Irritation: An immediate and intense burning sensation in the mouth, lips, and tongue.
Swelling and Blistering: The mouth, tongue, and throat can swell rapidly, potentially forming blisters. This can lead to a hoarse voice, muffled speech, and difficulty swallowing.
Gastrointestinal Distress: Nausea, vomiting, abdominal pain, and diarrhea are common after ingestion.
Increased Salivation: Excessive drooling often occurs as the body attempts to soothe the irritation.
Breathing Difficulties: While rare, severe swelling of the throat or mouth can obstruct airways, leading to life-threatening respiratory distress.
Skin Irritation: Contact with the plant's sap can cause a rash, redness, itching, and swelling of the skin.
Eye Damage: If sap gets into the eye, it can cause severe pain, redness, and potential damage to the cornea, requiring immediate medical attention.

Side Effects in Pets

Caladiums are highly toxic to common household pets, including dogs, cats, and horses. As with humans, the symptoms are caused by chewing on the plant and releasing the oxalate crystals.

Oral Irritation: Pets will often show signs of severe pain in their mouth, evidenced by pawing at their face or mouth and excessive drooling.
Swelling and Discomfort: Swelling of the mouth, tongue, and lips makes eating and drinking difficult and painful.
Vomiting and Decreased Appetite: Ingestion of the plant causes significant gastrointestinal upset, leading to vomiting and a refusal to eat.
Respiratory Distress: In very rare but severe cases, swelling of the upper airway can occur, making it difficult for the pet to breathe.

Comparison: Caladium vs. Philodendron Toxicity

Caladium is a member of the Araceae family, which contains several other common houseplants that also pose a risk due to calcium oxalate crystals. A common comparison is with the philodendron. Both are ornamental plants containing the same toxic principles, but their effects can vary in perceived severity.


Feature	Caladium	Philodendron	Comments
Toxic Principle	Insoluble Calcium Oxalate Crystals	Insoluble Calcium Oxalate Crystals	Both have the same primary toxin.
All Parts Toxic?	Yes, all parts are considered toxic.	Yes, all parts are considered toxic.	All plant matter poses a risk for ingestion.
Primary Symptoms	Immediate, severe oral pain, swelling, and burning.	Oral irritation, drooling, and digestive discomfort.	Both cause similar symptoms, but caladium reactions can sometimes feel more intense.
Risk to Pets	Highly toxic to dogs, cats, and horses.	Highly toxic to cats, dogs, and other animals.	Risk is similar for common household pets.
Risk to Humans	Causes severe oral and GI irritation, with potential for respiratory distress.	Can cause oral irritation and digestive upset.	Symptoms are similar, but caladium is often noted for more intense blistering and pain.

First Aid and Emergency Action

Immediate action is critical to manage the side effects of caladium exposure. For any potential poisoning, contact a poison control center (1-800-222-1222 in the US) or a veterinarian immediately.

For Ingestion: Do not induce vomiting. Instead, wipe out the mouth with a cold, wet cloth to remove any remaining plant material. Give the person or animal milk or water to drink to help dilute the toxins and soothe the irritation.
For Skin Contact: Rinse the affected skin thoroughly with water for at least 15 minutes to remove the irritating sap.
For Eye Contact: Flush the eye with a steady stream of water for at least 15 minutes. Seek immediate medical care if pain or redness persists, as corneal damage is possible.
For Severe Symptoms: If breathing difficulties or severe swelling occur, seek emergency medical or veterinary assistance immediately.

Prevention: Safe Handling and Placement

The best way to avoid the side effects of caladium is through prevention. Keep these plants in locations that are inaccessible to children and pets. When handling the plant for potting or maintenance, wear gloves to prevent skin irritation. When leaves begin to die back, discard them properly to prevent them from being accidentally ingested. For pet owners, considering alternative, non-toxic plants may be the safest option. A comprehensive list of poisonous plants for pets can be found on authoritative sites like the ASPCA website.

Conclusion: Prioritizing Safety Around Caladiums

While caladiums offer significant aesthetic appeal, it is paramount to prioritize safety. The severe and immediate side effects of caladium, caused by its calcium oxalate crystals, pose a real risk to humans and animals. From painful oral swelling to potential respiratory issues, the consequences of accidental ingestion are serious. By exercising caution, keeping these plants out of reach, and knowing the proper first-aid procedures, you can minimize the risk and ensure the health of your household. If an incident occurs, immediate contact with a poison control center or emergency services is the most critical step to take.

Frequently Asked Questions

The caladium plant is considered poisonous because it contains insoluble calcium oxalate crystals in all its parts. When the plant is chewed or ingested, these needle-like crystals cause immediate and intense irritation and swelling of the tissues they contact.

If a child eats a caladium leaf, they will likely experience an immediate burning and painful sensation in their mouth, lips, and tongue. This can lead to swelling, blistering, and difficulty swallowing or speaking. Seek immediate medical attention by calling a poison control center.

Do not induce vomiting. If the plant was ingested, wipe out the mouth with a cold, wet cloth to remove any remaining pieces. Give the individual milk to drink to help soothe the irritation and dilute the toxins, and call a poison control center immediately for further instructions.

Yes, skin contact with the sap of a caladium plant can cause irritation, redness, itching, and swelling, particularly for individuals with sensitive skin. If contact occurs, rinse the affected area thoroughly with water for at least 15 minutes.

If your pet eats a caladium, contact your veterinarian or the Pet Poison Helpline immediately. Common symptoms include pawing at the mouth, excessive drooling, vomiting, and a refusal to eat. Give the pet milk or water if they are able to swallow to help with the irritation, but never induce vomiting without veterinary guidance.

In most cases, caladium poisoning is not fatal for humans but can cause severe discomfort and potential complications, such as respiratory distress from significant swelling. In severe cases for humans or pets, or if a large amount is ingested by smaller individuals, the swelling could obstruct the airway, which can be life-threatening.

To safely keep a caladium plant, place it in an area completely inaccessible to children and pets, such as on a high shelf. Always wear gloves when handling the plant during potting or pruning. Consider safer, non-toxic alternatives for your home if pets or children are a concern.