Thank you for this interesting article.
My girl-friend just had a rash after eating shiitaké. The shiitaké mushrooms were fresh from the market, and I ate 3 of them raw and didn't feel any itchy sensation. However my gf started having A LOT of red marks and many small pimples all over her body (neck, hands, forearms, legs, hips...).
It really looked like hives so I gave her a histamine antagonist pill. No effect at all. I gave her another one (a different pill from another laboratory, stronger than the first one). No effect whatsoever.
A cream for Eczema reduced a bit the itchy sensation, but only for a limited time.
It's been 5 days now and she is still feeling itchy and she is still covered with red marks...
it is weird cause it really looks like hives or Eczema at first glance.