Subject: Re: Poison Oak-no laughing matter

From: PATTIBELLE <[email-masked]>
Date: Mon, 20 Feb 95 02:05:23 -0500

My doctor told me that at the first sign of poison oak to take one
Procardia pill, poke it with a pin, then hold it under the tongue
until all the contents have leaked out and been absorbed.  It stops
the allergic action right NOW!  However, he was going to e-mail me
some literature on it which he hasn't done.  Meanwhile, I'm afraid
to go out in the yard cutting brush for fear that I'll contract
another bad case of poison oak like I had last fall.  My sympathy
to you, Martha, and if anyone else knows anything about using
Procardia, please either post here or e-mail me!
 
Pat in Napa, CA

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From: [email-masked] (Peter F. Wick)
Date: 28 Feb 1995 22:23:21 GMT

>The following text was extracted from a post in rec.gardens.  It seems
|> >a little "off" to me, if Procardia is what I think it is. 

|> >//snip//

|> >> My doctor told me that at the first sign of poison oak to take one
|> >> Procardia pill, poke it with a pin, then hold it under the tongue
|
snip

|> Procardia is nifedipine, a calcium channel blocker.  
snip

I think some of the rationale lies in the ability of nifedipine to block
a specific type of calcium channel.  The dihydropyridines, of which nifedipine-
nicardipine-nimodipine-nisoldipine-nitrendipine-isradipine and others are,
(grammar?) selectively block L-type calcium channels.  So far there are known
to be at least 5 types identified by gene cloning.  L-type channels are
strongly implicated in dominating the release of stored chemical messages
from neuroendocrine (adrenal chromaffin cells), endocrine (islet cells) and
some white cells (mast cells).  If you can block them and prevent calcium 
influx into any of those cells, you inhibit release due to a stimulus.

My dissertation is on the coupling of L-type calcium channels to secretion
in chromaffin cells, but I'm not an expert on mast cells.  I guess this
hypothesis is similar to how cromolyn sodium and that other one in Tilade
work to stave off asthma and allergic reactions.  I don't know if the 
reaction comes on strong once the nifedipine leaves but I would bet it
does because the skin still will have the oils in it for several hours 
after the nifedipine has been cleared.  Oil present -> stimulate those IgE
mediated reactions -> suffering.  Maybe someone knows how to get in touch
with Bastien Gomperts in the UK.  Don't know the university, Liverpool?
He studies exocytosis using mast cells as a model and might have better info.

Peter Wick

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From: [email-masked] (Gregory W. Froehlich)
Date: 1 Mar 1995 15:09:49 GMT

> He studies exocytosis using mast cells as a model and might have better info.

Poison ivy causes delayed hypersensitivity reactions (T-cell mediated),
not immediate hypersensitivity (related to IgE and mast cells).
Avoidance, careful washing with soap if exposed, and use of
corticosteroids if a rash develops is a much way of managing rhus
dermatitis.

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Greg Froehlich, MD
White River Junction, VT