Terrible Coughing Fits

[Seahawks21]

Hello.  My wife is 34 years old.  A week ago she was perfectly healthy, and had never had allergies of any kind.  For the past week now, she has had terrible coughing fits, mostly through the night.  She will cough for minutes at a time, sometimes almost completely losing her breath.  She's lucky if she can go five minutes between fits.  She hasn't slept in a week.  She complains that it feels like there are thorns in her throat.  It seems to get worse in a few rooms throughout the house.  
We're thinking something is causing post-nasal drip of some kind.  The doctor gave her a steroid nasal spray.  We started trying nasal irrigation.  Both help a little, but not much.  I don't think it is pollen, as one of the rooms she coughs terribly in is a basement room.  I'm thinking dust or mold.  The weather changed and got warmer at about the same time this started.  She's completely miserable, in tears sometimes, and I'm getting pretty scared.  
She really doesn't have much for other symptoms.  No sneezing, no watery eyes.  Just a bit of a stuffy, runny nose, and this perpetual cough.  
Does anybody have any wisdom for us?  Could it be some sort of food?  How could this just start all of a sudden?  Do we need to wait for the steroids for a few weeks to see if they'll be more help?  We will be forever in debt for any help anyone can provide.  Thanks in advance!

Scott

[allmymarbles]

To confirm she is suffering from allergies, try having her take an adult dose of Benadryl before going to bed. If she doesn't cough then that is one question answered.

[evewisewoman]

Hello Scott,

I just finished reading your comments about your wife's coughing.
Before I was diagnosed with asthma, I had terrible coughing fits as
you call them. I would be fine, just sitting somewhere for example,
then I got this choking feeling. Then the coughing would begin and
I would cough so hard, tears would come down my cheeks. I remember
being in a lecture hall . I had to leave because I began coughing so
much. I was a little scared too and went to my family doctor.
She gave me a breathing test. I had to breathe into a tube. Anyway,
that was more than 10 years ago now. I didn't have asthma as a child.
I take daily asthma medication. My asthma came on fairly suddenly
too. Asthma can be inherited. I also had allergies before my asthma
was diagnosed. I'm allergic to house dust, chalk dust, june grass.
Anyway, I hope the cause of your wife's coughing will be found soon.
It is my hope that something I've written may be helpful. Be well. Eve :)