Aravaipa puzzle

[Whoever]

Linnea Ista wrote:
> 
> On 15 Aug 1996, Sylvester O'Farrell wrote:
> 
> >
> >     My friend hiked Aravaipa Canyon, AZ, which involved wading upstream.
> > Afterwards, she and her friend found themselves to have an itchy rash
> > over the body, 


> Sounds to me kind of like the "swimmers itch" I used to get sometimes in
> the summer swimming in certain lakes in Minnesota.  I also seem
> to remeber some correlation between this condition and waterfowl
> hanging out on the lake.
>  Just my guess!
> Linnea

Your guess is a good one; if this is "swimmer's itch", or Cercarial 
dermatitis, it is caused by the invasion of larval schistosoma flukes 
into the skin. The species that cause it are parasites of birds, but 
cannot mature in a human host; the cercariae die and the result is a 
painful edema and reddening, but repeated exposure causes papulae to form 
and a severe dermatitis.


J. Rinehart, Eastern Oregon State College