Poison Ivy: Plant Oil Causes the Rash
Poison ivy rash is the most common skin problem caused by contact
with plants. Urushiol, a naturally occurring oil found in poison ivy stems
and leaves, causes a rash when it comes in contact with human skin. The
red and itchy rash appears only in areas where urushiol touched the skin.
The rash may also be accompanied by fluid-filled blisters or hives, which
sometimes appear in straight lines or streaks. Urushiol can come in contact
with skin by way of clothing, pet fur, gardening tools, and other objects.
The more urushiol oil you come in contact with, the more severe the skin
reaction. A rash usually appears 12 to 48 hours after contact and will
continue to develop over several days. Once the affected area is cleaned,
the rash, if touched, will not spread.
Most poison ivy rashes can be treated at home. It is very important to
wash the area immediately after contact. Wet compresses and cool baths
will help relieve the itching and discomfort. Nonprescription antihistamines
and calamine lotion also may help relieve symptoms. Moderate or
severe cases may require treatment by a health professional.