Hi RB, I too am a sufferer and am suffering now too. Apparently it's apple blossom in bloom? Whatever it is I wish I didn't suffer!!
Anyhow, I use Benedryl and sometimes Claratyn depending which is on special offer! I've not had any problem using them, in fact without them I'd not be able to run as it brings on my asthma, which is allergy related.
I usually use Beconase too, but am seeing if I can go without that this season. I'm not sure as my nose is like a tap at the moment, so might end up taking it.
Sorry not much of a useful answer, only to say that taking the medicines shouldn't affect your race, but the symptoms could if not controlled!