The thing is that anyone can have a severe reaction for the first time after a lifetime of no symptoms.
By the grace of God, I'd finished flying when I went into severe Anaphylactic shock. First symptoms were severe itching of my hands while driving, of all places, from hospital.
I put a huge amount of work into finding out just what happened, and the only thing I could come up with is the strong soap in the hospital lavatory. To this day, my hands react to washing up liquid.
My GP told me of his father who also happened to be a GP. They were leaving a Chinese restaurant together, when his father suffered his first ever reaction. It was totally disabling.
I wrote this in a funny vein for JB, but believe me, it was far from funny.
http://www.pprune.org/jet-blast/2973...ml#post3654185