Negative Methacholine Challenge Test?

Question

Asked by Angel

Negative Methacholine Challenge Test?

Hi,

So I was treated for asthma for 5 years, and then a pulmonologist sent me for a methacholine challenge test, which was negative. However I have a positive reversibility of 13 and 15% on two PFT tests. My allergist says I have moderate asthma and has seen me very sick, while all of the pulmonologists I've seen say I don't and berate me for "wanting to take so many steroids". I do have trouble breathing several periods of year that last for weeks, and it is affected seasonally and in reaction to triggers (like smoke). Is it possible to have asthma with a negative methacholine challenge test? Is there something else to call this?

I feel like a fraud taking so much medicine, but at the same time I can't breath without it.

Angel

Answer

Here is a good post to review how asthma is diagnosed. As a general rule of thumb, a negative methacholine challenge should rule out asthma. However, the reversibility factor of 10-15% or better times two tests is also a sign that you do have asthma.

Perhaps the methacholine test was a false negative and should be repeated. This might be something to discuss with your pulmonoligist or allergist.

It may also be possible you have something other than asthma, perhaps another disease that is partially reversible with a bronchodilator, such as COPD. You can still get COPD if you have never smoked.

Your pulmonologist should be able to properly diagnose you in this regard so you can be treated properly and have some peace of mind.

It's never easy when your doctors have opposing opinions as to proper diagnosis. Usually in this case I'd recommend another opinion, although from what you describe here you've already seen more than one pulmonologist.

I wish I had an easy answer for you. I hope this helps. Good luck.

Answered by John Bottrell