As a poison ivy, if causes urushiol-induced contact dermatitis in most people who touch it, producing an itchy, irritating, and sometimes painful rash.

[4] They can be found growing in any of the following forms, all having woody stems: The deciduous leaves of T. radicans are trifoliate with three almond-shaped leaflets.

Identification by experienced people is often made difficult by leaf damage, the plant's leafless condition during winter, and unusual growth forms due to environmental or genetic factors.

Various mnemonic rhymes describe the characteristic appearance of poison ivy:[8] Caquistle or caxuistle is the Nahuatl term for the species.

[5] The plant is extremely common in suburban and exurban areas of New England, the Mid-Atlantic, and the Southeastern United States.

The development of real estate adjacent to wild, undeveloped land has engendered "edge effects", enabling poison ivy to form vast, lush colonies in these areas.

[25][26] Urushiol binds to the skin on contact, where it causes severe itching that develops into reddish inflammation or uncoloured bumps, and then blistering.

These lesions may be treated with Calamine lotion, Burow's solution compresses, dedicated commercial poison ivy itch creams, or baths to relieve discomfort,[27] though recent studies have shown some traditional medicines to be ineffective.

[28][29] Over-the-counter products to ease itching—or simply oatmeal baths and baking soda—are now recommended by dermatologists for the treatment of poison ivy.

[31][32][33][34] Others argue that prevention of lesions is easy if one practices effective washing, using plain soap, scrubbing with a washcloth, and rinsing three times within 2–8 hours of exposure.

Those affected can unknowingly spread the urushiol inside the house, on phones, doorknobs, couches, counters, desks, and so on, thus in fact repeatedly coming into contact with poison ivy and extending the length of time of the rash.

[37] If plant material with urushiol is burned and the smoke then inhaled, this rash will appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty.

[36] Urushiol oil can remain active for several years, so handling dead leaves or vines can cause a reaction.

In addition, oil transferred from the plant to other objects (such as pet fur) can cause the rash if it comes into contact with the skin.

[42] Similar reactions have been reported occasionally from contact with the related Fragrant Sumac (Rhus aromatica) and Japanese lacquer tree.

An astringent containing aluminum acetate (such as Burow's solution) may also provide relief and soothe the uncomfortable symptoms of the rash.