Toxicodendron refers to a group of plants related to sumac. Most people know at least one of these plants by its common name, such as poison oak or poison ivy.
Toxicodendron plants produce an oil that is irritating and toxic to humans, and the plants may be most known for their ability to cause this reaction.
Touching the oil from one of these plants is enough to cause a strong allergic reaction in many people. The plants have little use because of this toxicity. So simply put, people should do their best to avoid them completely.
Keep reading to learn more about Toxicodendron, including the uses, risks, and dangers.
Toxicodendron is a group, or genus, of woody plants in the Anacardiaceae family. The name comes from the Greek words for “toxic tree.”
The Toxicodendron genus includes a number of plants commonly known for their general toxicity, including:
- Toxicodendron radicans (poison ivy)
- Toxicodendron rydbergii (western poison ivy)
- Toxicodendron toxicarium (eastern poison oak)
- Toxicodendron diversilobum (western poison oak)
- Toxicodendron vernix (poison sumac)
Some lesser-known plants of the genus include trees native to Asian countries such as China and Japan, including Toxicodendron vernicifluum (lacquer tree) and Toxicodendron succedaneum (wax tree).
These plants contain a few different oils. The oil urushiol may be the most well-known, as it is responsible for the severe allergic reaction from the plants. Touching the plants may cause urushiol to move onto the skin, leading to irritating symptoms.
Other plants, such as mango trees, also contain this oil. Picking mangoes or touching the leaves and branches can also cause skin irritation, but this is less common.
Many of the Toxicodendron plants have little applicable use given their high toxicity. However, some of the lesser-known plants do see regular use.
The following are some of the more common uses:
The T. vernicifluum tree, also known as the laquer tree, is a source of laquer in countries such as China, Japan, and Korea.
Tapping the lacquer tree produces a large amount of sap. Manufacturers then filter and heat this sap to produce a durable lacquer.
Interestingly, the lacquer is still highly irritating, as it contains urushiol. However, it is less likely to cause a reaction after drying and curing has taken place.
The production of laquer from T. vernicifluum and T. succedaneum creates a high fat byproduct that makes an alternative to wax.
Known as Japan wax or sumac wax, it is an alternative to normal petroleum-based candle wax and burns without smoking.
Wax from the T. vernicifluum and T. succedaneum trees also makes its way into many cosmetic formulas, such as hair and skin creams. Manufacturers are much more likely to use the Rhus classification, which is an alternate classification for some plants of the genus Toxicodendron, for labeling purposes.
In its crude state, the wax has a rancid smell, which many manufacturers will process out. They will either sell the processed wax itself or other formulations containing the fatty wax.
Some forms of Toxicodendron, such as Toxicodendron pubescens (poison ivy), make their way into homeopathic formulas. The Food and Drug Administration (FDA) do not evaluate homeopathic medicines, meaning that they are not regulated or widely available.
There is limited evidence for the use of a highly diluted version of poison ivy for certain symptoms, such as inflammation from arthritis. For instance, one paper notes that in laboratory studies, the diluted compounds helped control the inflammation response, which could help with symptoms.
More research is needed to focus on the effects in both animals and humans.
Although Toxicodendron plants have some limited uses, they also pose a risk to many people, including:
Toxicodendron plants can cause potentially severe skin reactions.
Though it is not technically a poison, urushiol oil can cause a severe allergic reaction in many people who simply touch the plants. This reaction is called urushiol-induced dermatitis.
A study in the journal Dermatitis notes that contact with these plants is the most common cause of allergic contact dermatitis in the United States. As many as 50–75% of the population are sensitive to the compounds in the plants, such as urushiol.
A reaction to this oil can cause symptoms including:
- pimple-like spots, called papules
- streaks or abrasions in the skin
A person’s reaction to the oil can vary based on their individual sensitivity to it, as well as the contact duration.
Although some forms of allergic reaction clear up quickly once the irritant goes away, a Toxicodendron reaction can linger. For example, it can take 3–4 weeks after the first exposure for the symptoms to subside and the skin to return to normal.
In some cases, the reaction can even cause permanent scarring. This may be more likely in people with severe reactions who scratch their skin, leading to open sores or longer healing times.
Although reactions to urushiol can be painful, not everyone will have them. People vary in their sensitivity to urushiol. Some people may have little or no reaction when touching the plant, while many others can have very severe reactions from even small amounts of contact.
Urushiol comes off of the plant very easily, especially when a person breaks the leaves, stems, or branches.
This does not only apply to the skin, however. In fact, urushiol can also contaminate a number of other common objects, such as:
- walking sticks
- gardening tools
Additionally, if a person has this oil on their skin, it is possible to pass it to another person who touches the affected skin. Pets can also have the oil on their skin and share it with humans, or they might even have a reaction themselves.
Washing the affected skin should help strip away this oil and stop it from being contagious. Washing is also an important part of treatment, as urushiol is an oil that adheres to the skin.
As soon as a person notices any contact with one of these plants, they should wash the affected area vigorously with soap and hot water. Although there are specialized products designed to remove urushiol, a study in the Journal of the American Academy of Dermatology notes that simply washing is the most important treatment and prevention method.
Thoroughly washing any items that have touched the plants should also help remove the oil and prevent a reaction.
The safest route is to simply avoid contact with Toxicodendron plants and any items that may have touched one.
There is also a risk of people traveling in areas where these plants grow and misidentifying them. For instance, though it is not related to oak in any way, poison oak grows in a similar way as white oak and has a similar appearance.
Anyone who lives or hikes in areas where Toxicodendron plants grow should familiarize themselves with the specific types in their area and how to identify them. This can help prevent accidental contact and potential allergic reactions.
Toxicodendron refers to a genus of plants including poison ivy and poison oak.
Though technically not poisonous, the oils from these plants can cause allergic reactions in the skin from simply touching them.
Reactions from Toxicodendron can range from irritating to severe, and it can take some time for the skin to return to normal.
Some of the plants have limited use, but only after removing the irritant or making it inert.
It is simply best to avoid these plants, as they can cause uncomfortable skin reactions in some people.