i've had it all along!
actually got really bad a couple of times, but never stopped me from getting the medical.
i take sudafed ---the one marked non drowsy when ever needed, which sometimes is often, other times rarely if ever. and keep it in my flight bag. it was first recommended by a doctor that was giving me the first class medical in the states.
from time to time, it will give trouble with blocking of sinuses and ears, but so will colds and flus or being around cats. changing location of residence takes some adjusting to. when i do that, i take on a significant amount of local honey onto my toast etc to help accomodate my system to the local pollens. also bee pollen tablets appear to help as well.
but we get into the very fuzzy area of self help medical/ homeopath/vitamins gazeebo!
but never was a factor in the medical. just tell them what they ask and no more.