Methacholine Challenge

It's really not that bad. It's kinda like a really long Spirometry test. You have to be off of all asthma/allergy meds, no caffeine, chocolate, and a bunch of other stuff for several days in advance. You can use your rescue inhaler as needed. They don't want you to die before you have the test. They should give you a list of what you need to stop and when. For the test, you'll first breathe in a saline solution to get a baseline measurement. Then with each round they up the amount of methacholine. if you have asthma you should react with in the first few doses. If you do react by having an attack they will give you breathing treatments to reverse the attack before they let you leave.

That said, not all people with asthma will react to a methacholine test. I'm one of the people who doesn't react. It is the "gold standard" test for asthma, but sometimes there are false positives and false negatives. I've been to 6 different asthma specialists and pulmologists and while all while all my test come back normal, I have asthma. All the drugs I am on make a difference in my symptoms. Therefore I am diagnosed as having adult onset cough variant asthma. It did not grow up with asthma.

If you don't agree with your doctor, get a second, or third or fourth opinion, until you are happy with the results you are getting. You are your own best advocate.

hope that helps. sorry if it's a little confusing, i'm about to fall asleep.
~blue

I know it is frustrating trying to find a correct diagnosis. 

I went to four pulmanologist before I finally got diagnosed with asthma.  It took the methacoline challenge test to be positive about the diagnosis.  Most doctors wouldn't consider I had asthma because I never wheeze.  They blamed in on cardiac problems and everything else.  I finally found my last doctor who did the methacoline challenge test because he said my cardiologist was positive from all the testing I had done that it wasn't cardiac and some of the symptoms sounded like asthma.  It turns out I have severe asthma that went undiagnosed for many years.  If you take the test and it comes back positive I would try the asthma medicines and see if they help.  If they don't I would go to a large city with specialists and get a second opinion.  sometimes it takes a large number of doctors to find one to diagnose you.

I found the above comments very interesting as I am scheduled for the Metacholine Challenge. However, I may have to postpone again with my fall allergies being severe even with Zyrtec and Benadryl. (Last time I withdrew Zyrtec for 3 days I broke out in hives from my head to my toes!) My pulmonary specialist thinks I may have vocal chord dysfunction, with anxiety being a possible issue. He feels speech therapy may also help. However, he wants to rule out asthma first. I also feel that I do have asthma, having had shortness of breath as a child, especially on hot/humid days. Pregnancy was especially difficult. I have chronic cough everyday, triggered by anything or nothing: breathing in "wrong" (how does one do that?), giggling, the 1st taste of any/many foods, stress, smell of something strong, smoke, a turn of my head up or sideways, etc. Sometimes muscles constrict in the throat and I cannot get any air at all and have turned gray...an anaphylactic reaction. (Of course, these are worsened if I have a cold.) Please tell me if anyone has had these symptoms!