Subject: Poison Ivy/Oak

From: [email-masked] (Martin Rickwood)
Date: 7 Jun 1996 18:35:24 GMT

As a Limey living out in the States (North east PA) for the last two years
I am gradually becoming acquainted with the pitfalls of gardening over this
side of the 'pond'.  I have recently become 'acquainted' with either 
poison Ivy or Oak.

Could anybody tell me anything about these plants and their 'active' 
ingredients.  Can anybody let me know how to safely identify and 
dispose/irradicate.

Itching to hear from you all
Thanks 
them.

---

From: [email-masked] (Monique Reed)
Date: Fri, 7 Jun 1996 15:06:41 UNDEFINED

>ingredients.  Can anybody let me know how to safely identify and 

The poison ivy/oak rash is caused by an antibody/antigen reaction.  After one 
or more contacts with P.I.,  your body creates antibodies to the compound 
formed when the P.I. chemicals bond with the skin.  The antibodies take 5 to 
21 days to develop, and you might well NOT get P.I. the first time you 
are out in it.  When you have the antibodies and you encounter the plant, 
WHAM, the antibodies are ready to attack the antigen, resulting in the 
familiar itchy blisters.  The rash develops 12 to 48 hours after exposure, 
which is why it often seems that scratching the blisters makes new blisters 
appear elsewhere--not true, one is only watching new blisters appear; the 
fluids in the blisters do not spread the rash.  It is easiest to get on 
tender skin (faces, necks, genitals) and hardest on tough, oily skin (palms of 
hands, etc.)  True immunity to PI occurs in 15 to 30% of the population, but 
beware---you can develop senstivity at any age!

How not to get P.I.?  Step one:  Learn what it looks like.  "Standard" P.I. 
can be herbaceous, viny, or shrubby, and it often climbs trees.  It has 3 
leaflets which can be entire or toothed.  When it climbs, the stems often have 
aerial rootlets.  It never has tendrils or prickles, so if you see a 3-leaved 
vine with either, it isn't P.I.  The flowers are small and greenish; the 
fruits are white.  Fall color is often a cheerful red.  All parts of the plant 
are allergenic, including the pollen and (for sensitive individuals) the 
smoke from burning foliage.    P.I. grows in almost every state in the 
union (I heard there was none in Nevada?)  It is most common in disturbed 
areas--trailsides, vacant lots, along railroads and highways, etc.  Any 
guidebook worth the cover price should have an illustration.

( P. oak isn't common where I am; maybe someone 
else can tell us what it looks like and where it hangs out?)

Step two:  Wear protective clothing and avoid the irritant.  If you know 
you're going to be out in it, wear long pants, closed shoes, and long sleeves. 
 Wear gloves if you are going to be cutting brush, and a hat or sweatband so 
you won't be tempted to wipe your face if you sweat.  Avoid touching clothes 
you know have been in P.I.  Come home and undress into the washer and wash the 
P.I. clothes by themselves.  Realize that you can get P.I. from shoes, 
clothes, backpacks, PETS--anything that has the irritant oil on it.  
Washing these things with soap and water removes the irritant.

Step 3--Get the irritant oil off as soon as possible.  P.I. takes about 10 
minutes to penetrate the skin, so if you can, wash with lots of water.  Soap 
is okay, but be careful--it removes your skin's protective oily layer, leaving 
it open to attack if you have P.I. irritant anywhere else around to get on it! 
 Ditto for alcohol-type solvents.  The idea is to get the irritant off without 
spreading it around.

Step 4--Medical treatment.  If you are going to get P.I., the quicker you can 
get topical steroids on, the less severe the reaction will be.  A severe 
case--face, genitals, over 25% of the body--needs attention from a physician, 
who will likely administer an injection of steroids or prescribe oral doses.  
While you have the blisters, avoid scratching as they can become infected.  
Cool, moist, compresses feel good.  Calamine lotion or other soothing lotions 
may help, but avoid anything with anaesthetics (like benzocaine), alcohol, 
camphor, or metals (zinc oxide, iron compounds, etc.) as they are further 
irritants.  Antihistamines are not effective.

(The above based on info in the AMA Handbook of Poisonous and Injurious 
Plants, ed. Dr. Kennthe Lampe, copyright 1985 by the AMA.)

Home remedies--Everyone has one.  Various plants, (e.g. Jewelweed) are 
purported to stop P.I.  Other folks swear by gasoline, bleach, etc.  I've 
never had the occasion to try any of these--use at your own risk.

How to get rid of P.I. plants---Good luck!  It can be tough to get rid of.  
P.I. responds to Roundup, and you can apply the herbicide with a wick 
applicator if you don't want to get near the plants.   Keep after it; it can 
take several applications!  A good solution is to hire someone who is truly 
immune to get rid of it for you.  If you plan to burn the pulled-up or dead 
plants (if this is legal where you live), remember that the smoke is toxic, 
too--try to burn on a still, damp day so it doesn't spread.  Keep kids and 
pets out of debris piles.

One final note:  if you are severely allergic to P.I., you might want to be 
leery of mangoes and cashews.  They're in the same family and if you're 
hyper-senstive, you may be allergic to these as well...

I know this was long, but I hope it helps.  Let's be careful out there!

Monique Reed
Herbarium Botanist
Biology Department
Texas A&M University
College Station, TX  77843