I have it too, but don’t know if it’s MS related. I’ve always been a bit prone to bronchial problems, even as a child. Winters were one long cold, and I once had a congested lung.
Lately, I’m not such a martyr to colds, but I have an almost constant tickle, and problems with catarrh. I also find I can’t talk very long without my voice getting hoarse. People ask if I’ve got a cold, when I haven’t. I do think it has slightly worsened over the time period that I believe I’ve had MS (which is much longer than I’ve been diagnosed), but I can’t be sure whether it’s related, or just “normal for me”.
My mother, who doesn’t have MS, is also like it, so it may be genetic. I think it could be linked to asthma, as I used to have an inhaler for asthma, but never got on very well with it, as I found that when maximum need arose, I was unable to inhale the spray, as it tickled and made things worse.
I find I get worse in the presence of strong smells, like frying or cigarette smoke, if there’s an abrupt change of atmosphere (e.g. coming indoors from a cold day), or lying down.
None of this really answers you, I know. And I can’t tell whether it’s an MSy thing or not. Oh, and I can’t go anywhere without a hankie, either. If I realise I’ve left the house without one, I have to go back, or stop at a shop to buy some tissues. It’s not just psychological. I know I can’t make do without one.