Landscape Architect Articles

A Touch of Poison08-05-13 | News

A Touch of Poison

Poison ivy grows throughout all U.S. states east of the Rocky Mountains. It is normally found in wooded areas, especially along edge areas where the tree line breaks and allows sunshine to filter through. It also grows in exposed rocky areas, open fields and disturbed areas.

A constant menace to landscape professionals is exposure to plants that cause an adverse reaction. None might be so feared, and misunderstood, as poison ivy, poison oak, and poison sumac.

All three can cause a skin rash, sometimes severe, when they touch your skin. The results can be a red, uncomfortable, and itchy rash that shows up in lines or streaks and is marked by fluid-filled blisters or large raised hives.

The rash is caused by contact with an oil, urushiol, that is present in all parts of the plants, including the roots. Urushiol is an allergen so the rash is actually an allergic reaction.

The rash usually appears eight to 48 hours after your contact with the oil but it can occur as quickly as five hours and as late as 15 days. It usually takes more than a week to show up the first time you come in contact with urushiol but it develops much more quickly after subsequent contacts. The more urushiol you come in contact with, the more severe your skin reaction.

The rash can continue to develop in new areas over several days. Most rashes can be treated successfully at home. Washing off the oil is the first line of attack. To relieve symptoms, use wet compresses and take cool baths. Nonprescription antihistamines and calamine lotion also may help relieve symptoms.

What many do not realize is:

The rash is not contagious. You cannot catch or spread a rash after it appears, even if you touch or scratch the rash or the blister fluid, because the urushiol will already have been absorbed or washed off the skin. The rash may seem to be spreading, but either it is still developing from earlier contact or you have touched something that still has urushiol on it.

Not everyone will develop symptoms, as some people are not allergic to it. And those that are allergic to it will differ in their sensitivity to it. Severe reactions include swelling of the face, mouth, neck, genitals, or eyelids, widespread, large blisters that ooze large amounts of fluid, and a healing time of up to six weeks. Some cases might require treatment by a doctor, who may prescribe corticosteroid pills, creams, ointments, or injections.

Wearing protective clothing from head to toe will not totally prevent a reaction. If urushiol gets on clothing or tools and you touch them later with bare skin, like wiping your brow with your sleeve, you have been exposed.

The only sure way to prevent a rash if you are allergic is to learn to identify the plants so that you can easily avoid them.