Mushrooms are not just a food now. Remember they are now being used in skin care lines such as some of the Aveno skin care products. It's a nightmare when I go for my annual mammogram as I usually have to go through at least 2 technicians before I find one that is not using Aveno with Shitake mushrooms on their skin or one that is not taking a mushroom supplement tablet every morning for anti-oxidant purposes.
My allergist told me a person can develop an allergy (yes, even severe) at any time to any thing. I ate mushrooms for 31 years. One day, 20-30 minutes after eating some mushrooms on a salad, I doubled over with stomach cramps and had blow out intestinal problems for 3 hours straight, non-stop. I thought immediately of the mushrooms, but thought it was food poisoning. Exact same thing happened 2 months later with 4 slices of mushroom spread over 2 pieces of pizza. A few months later, gave it 1 more try with 1 slice of mushroom -- exact same result. Finally realized I had a severe allergy. Thinking back, for 2 years prior to the first massive reaction, I'd had stomach aches after eating foods that had mushrooms or mushroom powder in the sauce. I never connected the two, just thought it was the rich sauce being too rich for my stomach.
Epipen Injector and Claritan Readitabs (instant melt, enters your system immediately) are now carried with me at all times. I do not eat at all in any restaurant that serves mushrooms. Restaurants (especially fast-food where there are flat grills and several things cooked on the same grill) do not understand the cross-contamination issue. Made to order omelet bar at a buffet -- out of question since someone before me likely had mushrooms in their omelet. Salad bar -- even if I skip the mushrooms, most restaurants tell me they chop all the veggies on the same cutting board early in the morning without washing the board in between different vegetables.
Asked my allergist if I was being paranoid, and he said I was doing exactly what I should be doing. He then cited ER stories of patients who were less diligent or restaurants that were less diligent and patients were exposed to their trigger allergen through cross-contamination incluing kissing their spouse who'd eaten something early in the morning to which the patient was
allergic (and reacting even though spouse had had other meals and drinks since then).
As mushrooms gain popularity, my joy of eating out diminishes. And while I do not hestiate to shake hands with men in business, church, etc., settings, any time I shake hands with a woman, I head to the ladies room and wash my hands immediately in case they use lotions, etc., with shrooms in them. And then I use a paper towel to open the door to exit because, what do women do the ladies room after washing their hands? You guessed it, they often apply a fresh layer of whatever lotion they carry in their purse!