I've got the allergy meds although a great many of my brothers and sisters can't afford it. But that is not my question. The question is what possible utility does hay fever serve?
We are in a unique position as a species. We are at a level of development and safety in population where even the weak can survive long enough to reproduce. Those with Asthma, for example, might have died young naturally. Now it’s a manageable irritation for most sufferers and they go on to live full lives, have children, pass on their genes, die of old age. Detrimental genetic defects are passed down routinely and are ever present in the gene pool, because we are not positively selecting for health benefits or environmental benefits. Sure, we have the odd beneficial mutation here and there - sickle cell anaemia for example, as trade off for increased resistance to malaria - but its more often than not isolated cases or populations, or a single family line living in a place where many family lines exist alongside each other enjoying the same security, well-being and status.
In order for our physiology to change in any real way, we’ll have to do it either artificially, or suffer a global crisis or massive shift in environment. Dramatic changes in our environment may force dramatic changes in us, provided they come before we are ready to handle them. It is much more likely that we will see
degradation in faculties because of, for example, our increasing reliance on and substitution of technology for basic functions.