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Date of last update: 10/19/2017.

Forum Name: Asthma

Question: Methacholine Challenge Interpretation

 REVJR1 - Sat Sep 26, 2009 9:15 am

I'm a 39 year-old male. I've been experiencing severe throat tightness, throbbing above the roof of my mouth, and burning/pressure in my back upon inspiration for about six months. Spirometry values were normal, but a methacholine challenge, according to the respiratory therapist, indicates I have asthma (follow-up with pulmonologist next week).

My question - is there any significance to the fact that my reaction to the challenge occurred on the final, most concentrated level of the methacholine? Function decreased by -23% at that point, and I understand that -20 is the guideline for asthma diagnosis. I'm just wondering if this might be GERD-related or seasonally induced because I've never actually had an attack. I've been on QVar for 2 months, prior to the spirometry, and it has done nothing for me.

 John Kenyon, CNA - Tue Nov 03, 2009 10:40 pm

User avatar Hello -- You've been accurately diagnosed with asthma, the only question remaining being: What exactly is the underlying cause? Many cases of asthma are either seasonal (airborne allergens) or due to GERD, and in these cases the underlying cause must be treated as well as the symptom itself. The threshold for decreased function is largely arbitrary and the fact you didn't cross that threshold til the peak level of the challenge is splitting hairs. You've been symptomatic for six months, but as with many people, the absence of an acute episode with wheezing leaves you assuming you haven't been affected by asthma per se. The symptoms speak for themselves, and the duration strongly suggests GERD as the underlying cause. The needs to be explored independent of the pulmonary inflammation, which also needs to be treated on a regular, therapeutic basis at least until the underlying cause has been managed. If the symptoms disappear then, most likely all you'd need is to carry a rescue inhaler in case of a random severe episode.

Hope this is helpful. Good luck to you and please do follow up with us here as needed.

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