Diagnosing A Poison Ivy Rash
The toxin in poison ivy that causes contact dermatitis is an oily substance called urushiol, found in all of the parts of the plant. This is why poison ivy is a threat year-round, not just when it is in leaf. It's possible to pick up the toxins from garden tools, clothing, pets--anything that has been in contact with the plant.
Once it touches the skin, the urushiol begins to penetrate in a matter of minutes. In those sensitive to the chemical, reaction will appear in the form of a linear rash (sometimes resembling insect bites) within 12 to 48 hours. Redness and swelling are followed by fluid filled blisters and severe itching. In a few days, the blisters become crusted and begin to scale. The dermatitis usually takes about ten days to heal, sometimes leaving small pigmented spots, especially in dark skin.
Treating Poison Ivy Rash
Immediately following a close encounter with poison ivy, wash all exposed skin areas with cold running water; preferably within 5 minutes of contact. Poison ivy rash itself is not contagious. Only the offending chemical--urushiol--is spread by contact.
Swab the exposed area with rubbing alcohol to dissolve any residual oil.
Avoid scratching the blisters. Although their fluid will not spread the dermatitis, fingernails may carry germs that could cause an infection.
Take cool showers to relieve itching; use over-the-counter preparations like calamine lotion to relieve mild rashes. Soak in a tepid bath with oatmeal or baking soda to dry oozing blisters and get some relief.
Hydrocortisone creams available over-the-counter are not effective. According to dermatologists they are not strong enough.
Avoid caffeine and alcohol which aggravate itching.
Do not pet animals that have wandered through poison ivy, as the toxic oils are on their fur. Check with a veterinarian on how to remove them.
If you are routinely exposed to possible poison ivy contact you should consider buying a product called IvyComplete. It contains three bottles – IvyBlock to prevent a rash, MyCleanse to remove oil immediately after contact, and MySooth to relieve itching if you didn’t catch the oil soon enough (www.ivyblock.com).
For severe rashes, consult your doctor or a dermatologist for treatment.
Some More Advice
This section below is from a posting on the wonderful gardening blog called Garden Rant (www.gardenrant.com), copied with their permission:
So here's the question: When I think I've rubbed up against some, I should run into the house and do what?
Raver mentions that there's conflicting advice on this score and recommends her own favorite tactic - "jewelweed, a soft, green-leafed plant with little orange flowers that often grows next to poison ivy in damp areas, near streams." Its stems and leaves should be crushed and rubbed on the PI sap. And guess what - Umar uses it himself and keeps it handy in ice cubes form. Well, that's interesting but what's a jewelweed-less gardener to do? Let's consult the handy links on Umar's site.
From Ohio State: "If contacted, affected areas should be washed immediately with soap and water as well as any clothing or objects that may have come in contact with the oil. This activity will not decrease the severity of the reaction, but it will lessen the chance of spread." Oh, that's encouraging.
Referring to both poison ivy and oak, his California source writes: "After coming in contact with the allergen, the best way to prevent skin irritation is to pour a mild solvent, such as isopropyl alcohol (rubbing alcohol) over the exposed area and then follow this with plenty of cold water (warm water enhances penetration of the oil) within a few minutes of exposure. If isopropyl alcohol is not available, just wash with lots of cold water. But you need to wash within 5 minutes of exposure to prevent a rash. Even if it is too late to prevent the rash, washing the skin to remove excess plant oil will keep the rash from spreading.
"Using only a small amount of water or disposable hand wipes is more likely to spread the toxin than remove it. Soaps can be used to wash, but only if used with copious amounts of water; otherwise, they too will spread the toxin.
"If a rash develops after exposure to poison oak, the use of a product called Tecnu, which is sold at most drug stores, will relieve the itch and reduce the rash. When applied once a day, it stops the itching for most of the day and clears up the rash in about 7 days."
Thank you, UC Davis! This information is so complete that I want to kiss those hort geeks. Not for them the usual tepid, CYA nonanswers given by so many academic sources. They also confirmed what I'd read long ago, that sensitivity to poison ivy increases with each exposure, so don't anybody assume you're immune because the next run-in with it could change all that.