Originally Posted by azmojo

And why, if an allergy was such a lethal threat to someone's existence, would they risk their life and RELY on the compliance of 100+ other passengers? If it's legitimately such a threat to someone's existence - particularly a 2 year old - then why take that chance?

In many Asian countries, it's extremely common to wear masks when they have a cold so as not to spread the germs. I don't see why this is a big ask.