on hay fever... I've had cromolyn work during that level of attack. Standard max dose and the effects work their way through/to the mast cells. So, might still be worth trying if a reoccurrence of last week's attack happens or could happen.

I take a maintenance dose every 2 days through summer (because of tree species that I'm not allowed to systematically hunt down and destroy. But then humanity can't yet decide if its ok to kill off the mosquito), plus extra for days like a recent visit to a relative's dusty house.