Poison ivy is a plant whose sap contains an oil called urushiol. Contact with this oil, which may be present on the roots, stem, or leaves of the plant, causes an allergic contact dermatitis. If a person gets urushiol on the fingers, it may be transferred to other parts of the body by touch. The rash often occurs in lines where plant leaves brush against the skin. A rash takes a day or two to appear after a plant is touched. Be sure your family is very familiar with the appearance of the plant; here is another photo.
If your child has touched poison ivy, wash all parts of the body that may have been been in contact with the plant with soap as soon as possible. It takes some minutes for the oil to be absorbed, so washing can prevent the rash if done promptly. Wash the clothing, and be aware that the urushiol on clothing can lead to a rash in someone who touches the clothing, so be careful.
Mild cases of poison ivy can be treated with an over-the-counter steroid preparation such as hydrocortisone cream 1% applied three times a day. Calamine lotion can relieve itch. Some cases, however, require an oral steroid to be treated effectively, so visit your doctor if the rash is widespread or does not respond to these measures.
