telster: thanks for the post. I also agree that LondonJ's decision (to land the plane) is a 100% well-done, and it's no use to diagnose onboard. Even if I were the pilot, I would have done the same.
But
after reading the post (as everyone does here), the chance of anaphylaxis can really be ruled out, not inflight, but afterwards. Everyone made their guess after reading the post, not inflight. So, if reading the whole pic (esp that patient became fine after 40 mins), I wouldn't propose anaphylaxis.
Anyway and again, J has done a good job!