Poisonous Plants

Symptoms of exposure

Exposure to plants of the family Anacardiaceae, especially Toxicodendron spp. (e.g., poison oak, poison ivy, poison sumac), can cause any or all of the following symptoms:

• Itching
• Red streaks or lines where the plant brushed against the skin
• Small bumps
• Large, oozing blisters

Cause

An irritating, oily sap called urushiol triggers an allergic reaction once it comes into contact with the skin. A person can be exposed to urushiol directly or by touching objects that have come into contact with the sap of one of the plants.

Prevention

The following practices can greatly decrease your risk:

• Learn to identify the plants to avoid contact.
• Carefully remove plants from areas around your home.
• Cover skin with clothing (long-sleeves, long pants, socks and shoes) when walking in wooded areas.
• Be aware of resins carried by pets.
• Use over-the-counter skin care products that can help keep the urushiol from getting into your skin.

Treatment

Use these treatment procedures:

• Immediately wash areas of skin that may have touched the plant.
• Apply wet compresses or soak the area in cool water.
• Use over-the-counter products, such as Hydrocortisone 0.5% or 1%.
• For a moderate or severe rash, visit your health professional. Prescription medication may be necessary.

Descriptions and habitats of plants to avoid

Poison Ivy

Poison Ivy has slightly glossy green leaves that grow in groups of three. The leaf shape may vary, and the plant may grow as a vine or as a trailing or low shrub.

It grows as a climbing vine in the east, midwestern, and southern states, and as a non-climbing shrub in the northern and western states.

Poison Oak

Poison Oak has leaves that are shaped somewhat like oak leaves. The underside of the leaves is much lighter green than the surface and is covered with hair.

It grows as a small shrub in the sandy soil of the southeast, and as a very large shrub or vine in the western U.S.

Poison Sumac

Poison Sumac is a small tree about 5 to 6 feet high. Each stem contains 7 to 13 elongated leaves without teeth, arranged in pairs.

It grows as a shrub or small tree in the northern U.S. peat bogs and in swampy southern regions of the country.