Like other readers, I have always heard that Impatiens worked on the
"sting" of the stinging nettle. Like others, I have found this to be
true..much experience as a wildlife biologist. I have NOT found it true
that one can wash off the nettles once they have gotcha, so I must disagree
that the Jewelweed simply acts as a wild "wet-wipe." My skin sense something
akin to Aloe extracts (another thread that was explored in depth here last
year). I would disagree with the poster who suggested tannins in the
plant act as an astringent - Jewelweed is low in tannins.
I have not tried Jewelweed as either a preventative or a treatment for
PI. I am simply not allergic to it. This also confirms the post suggesting
it is an immune response rather than a dermatological reaction to an irritant;
but I hasten to add that the oil IS, indeed, an irritant as well! This nasty
plant does you in with a double whammy - if your skin is not calloused, you
get a relatively quick skin reaction; later the immune response kicks in and
the welts and blisters become visible.
People ofetn develop reaction to PI even after years of resistance (so I still
take precautions). My medical friends tell me that the products sold to help
you gain an immunity are , for the most part, bogus.
Helpful hint - as a previous post says, wash as soon as you can.
...BUT DON'T use soap. Evidence (recent) suggests that the soap will
move the oils (of both your skin and the PI), but will often allow
you to REDEPOSIT some of the urushiol back on to your now unprotected
skin. Current medical advice and the latest word from the US Fish and
Wildlife Service confirm this.
Also, remove clothes and wash them separately (so other friends and family
don't get it from your contaminated clothing).