How affective is the methacholine challenge test for asthma?
I went to the Dr the other day because I been having SOB and wheezing at night. I had bronchitis about 2months ago but my symptoms never really want away. I did the lung function test and the Dr. said I was borderline. I asked him about the meth test and he said that really isn’t that accurate he said I could have a positive result and not have asthma or I could have a negative result and have it. I am allergic to dust mites, cats, dog, grass, oak tree and mold. So right now I am taking pulmicort and Nasonex and I have an albuterol inhaler. So I was wondering if this is true about the methacholine challeng test
Written by Admin on October 14th, 2009 with
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#1. October 16th, 2009, at 12:15 PM.
Go to, select the ATS (American Thoracic Society) Statements/Guidelines link, scroll down to Pulmonary Function and download and read the guidelines for Methacholine and Exercise testing (a PDF file).
Methacholine challenge testing is a better predictor of not having asthma than of having asthma.
As I tell my patients when I am testing them, at this stage (Methacholine challenge) we are essentially trying to prove that you don’t have reactive airways. Why? So that you don’t spend your life on medications that are of no benefit to your health. So that your physician can better pursue the source of your distress and ultimately provide better management of your health.
You need to have spirometry performed at a real Pulmonary Function Laboratory (not in a doctor’s office) to rule out obstructed airflow. You need to perform the spirometry both before and after using a bronchodilator (this is all done in the lab). If the results are normal and asthma is a suspicion, then your next step is the Methacholine challenge.
You must follow pre-test instructions carefully in order to obtain accurate results. Your spirometry and your methacholine challenge need to be performed on different days.
Good luck and ask for a pulmonary consult if you need one.