Can we trust the "How to avoid poison ivy rash" video?


#1

The comment link for the “How to avoid poison ivy rash” post isn’t working, so I’m asking here. Can we trust the info in this viral video? His credentials sound right for the task. On the other hand, he seems to mispronounce urushiol (“oo-roo-shee-awl” according do dictionary.com and http://www.toxipedia.org/, if those sites are correct).

His washcloth trick seems a great way to spread urushiol all over your body. But he says not:

[quote] There is a reason every mechanic in the world carries a grease rag in
their back pocket. It is because friction with a cloth is the best way
to remove grease and oil from the skin. Whether you get some back on
the skin is not as important as the very effective removal from the
skin. It is important to vigorously wash the skin and toss the rag
directly into the wash with a good detergent. Using two or three wash
rags is a good idea but I have not found it to be necessary. I use the
loofah last as a means to remove any residual amounts. It is so porous
it is unlikely that you will recontaminate your skin with the tiny
amounts you are removing with this last wash with the loofah. As far as
contaminating your clothing, the detergents and long wash and rinse
cycles in a standard home washer will efficiently remove all oils and
grease through the formation of water soluble micelles that carry the
oils away (oil and grease stains in clothing are from contaminants, not
from the actual oil or grease. I would not be at all concerned about
that. Many of the experts you hear that from have made up a reason for
continued recontamination, usually because they did not effectively
remove it from the skin in the first place. These are the same
nincompoops telling you to not rub it off with a rag in the first place.
Therefore they ensure that they will get severe ongoing reactions,
then they make up reasons for the continued reactions. The video is
showing you the common sense reality that you need friction to
effectively remove oils and grease from the skin.[/quote]

“Kelly” responds:

[quote]Anyone who has spilled cooking oil on clothes knows that the oil can get
fixed in the fibers, particularly cotton. If you catch it right away
you can get it out with a direct prewash treatment with Dawn, but once
it’s been heated and polymerized, it is nearly impossible to remove. I
would suspect that Urishiol is the same. I don’t know at what
temperature/time factor it polymerizes, but it might be smart to avoid
the dryer and wash in warm water with extra detergent.[/quote]

And, in fact, Urishiol is made into lacquer through oxidation and polymerization, so it seems pretty plausible that it could stay in your clothes a long time, even after washing, depending on the conditions - especially for anything that went a long time before being washed.

Jim notes, though:

[quote]As guy who spent much of my career in polymer science, I can tell you
that once a monomer is polymerized, it will no longer have the chemical
properties it originally had.[/quote]

From what I’ve read in the past, urushiol in poison oak/ivy chemically bonds to your skin within as little as 30 minutes, making washing it all off hours later impossible, even with soap or detergent. The price gouglingly expensive Zanfel scrub claims to chemically bind with urushiol to get it off, but I have to wonder if the key to its supposed effectiveness is actually the microbeads scrubbing off the skin that has chemically bonded to the urushiol? Or just the same scrubbing action “Dr. Jim” refers to to get oil off of one’s skin?

Dr. Jim’s take:

[quote]Zanfel does absolutely nothing to get rid of the itch once the
reaction has started. If you do a search on the ingredients you will
find they are ingredients in many other cleansers and detergents. It
has little fragments of polyethylene in it that make you feel better
while scratching. You pay about $30 an ounce for that feeling when you
could by Mean Green Power Hand Scrub for $0.37 and ounce and get exactly
the same feeling.
If you get relief from using Zanfel it is probably because you ran
hot water on the area while using it, or because of the placebo effect,
not because of any of the ingredients in the Zanfel. It can do nothing
to reduce the itch. If the ingredients in Zanfel could really make their
way through the cornified layers of your skin (it can’t) you would
probably have a worse reaction to it than to the poison ivy.[/quote]

Anyway, I used to wear disposable gloves until I found out that urushiol can actually go through gloves! You need to use heavy vinyl gloves to avoid penetration.

Dr. Jim notes this as well, in a different post:

[quote]Urushiol is slightly more water soluble than the grease I used in the
video. But just slightly. It consists of a long chain of carbon
molecules that are mostly hydrophobic (non-reactive with water), but on
one end it has a couple of oxygen molecules that are able to interact
with water (not very strongly). But it is not very soluble in water.

Since it is an oil, it will react very easily though with things like
rubber gloves and rubber boots. You should never try to protect your
hands with rubber gloves. Use vinyl instead. Because Goretex is highly
hydrophobic, it too will interact with urushiol easily.[/quote]

Notable is that Dr. Jim does not seem believe in systemic reactions to urushiol (from his Q&A):

[quote]Most people get it on several parts of their body. But it is not because
it becomes systemic and finds its way back to the skin. Once it makes
its way to the bloodstream it is over. If your son got it on other parts
of his body it was moved via contact with oil that was not removed
either from his skin or some other contaminant.[/quote]

Not sure what data or studies he has to back up that assertion, though.


#2

You should contact the chemist in this Britannica video produced by the American Chemical Society and tell her that she isn’t pronouncing “urushiol” the way you think it should be pronounced, based on your deep research.

https://www.britannica.com/science/immune-system-disorder/images-videos/Learn-how-the-oil-urushiol-secreted-by-poison-ivy-causes/207802


#3

Do tell, which is the correct pronunciation? I cited two sources, and even explicitly wrote “if those sites are correct”. I’d be grateful if you could resolve the issue :smiley:


#4

Great debate, this. Alas untimely, as I got poison ivy camping this weekend. Gonna be a rough 10 days.

My issue is that I only seem to need a very small exposure to it, meaning I often miss when I am exposed. And of course it takes days for my skin to react, so by the time it is recognizable as more than a bug bite, it is EVERYWHERE.


#5

All I’ll say about this is that you should ask three chemists to pronounce “amide” the same way and see what happens. Seriously, pronunciation means nothing when it comes to whether or not a chemist knows their shit.

If it’s polymerized by oxidation, I wouldn’t think it would still be active enough to cause a reaction. I’d believe that it impregnates into the fibers and doesn’t come off without repeated washings, but it looks to me like it would epoxidize to form polymers, which really limits the functionality of the substance.

Overall, the chemistry sounds right, though. It’ definitely more of an oil than anything, and treating it like a grease is probably the best course of action.


#6

My point is, you started off by making a big deal out of the way he pronounces the word, stressing that someone who pronounces it “wrong” is not to be trusted. That’s ridiculous. So many words can be pronounced in multiple ways. You know that, so why even bring it up as an argument about whether or not to trust the information in the video?


#7

Well, I did consider using a smiley after that point. :smiley:
While my bit about the pronunciation was a bit facetious, I was serious about whether we can trust the video. I don’t necessarily trust anyone completely, especially on topics that are controversial and are rife with misinformation. It was a genuine question, not a Betteridge headline.

Given the full content of my post, with extensive quotes that let Dr. Jim speak for himself, I think you may be being a bit persnickety about that one line :slight_smile: (I know, I know, me, the persnickety one, saying someone else is maybe being too persnickety…but who better to recognize such behavior :flushed: )


#8

You have my sympathy even though as far as I know I’ve never had a case, even though I’ve fallen into patches of it.

I still avoid it. There’s no telling when that might change.


#9

ALUMINIUM!  


#10

I think he’s right. I’ve read (and have noticed) that where your skin is thickest, you get it less – and where it is thinner you get it worse.


#11

Hot water (as hot as you can take it - basically just shy of scalding yourself) on poison ivy helps a lot – temporarily itch relief and boy does it feel gooooooood. I imagine it feels a lot like what some illicit drugs might feel like.


#12

As a lad, I did a fair amount of hiking in backcountry areas rife with poison oak. More than once I seemed to find myself protected by a heavy sheen of sweat, if I managed to get home and shower in hot water before the sweat dried. If not, I’d get reeeeal itchy.

Learning of the hydrophobic nature of the oil makes it seem like my youthful suspicions were correct.


#13

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