I haven't had the methacholine challenge specifically, but i've got a lot of things that point towards asthma as it is. I was born with very severe skin allergies to everything, and suffered from it (it was just about untreatable it was so bad) until I was 12, when things calmed finally, all on their own. A few years later, my allergies were back..they had settled in my nose(eustachian tube) and lungs. Apparently I had a 50% risk of developing asthma, 70%+ for allergic rhinitis from the start, and it's common to develop that after it seems like skin allergies have calmed. Plus allergies and asthma are rampid in my family. I have had pulmonary function testing which showed little obstruction(within normal range), but then again I had recently been on prednisone and was doing great that day. For some reason I had no increase that day also in taking a ventolin inhaler(at a specialists). But a few weeks earlier, I had been given nebulized albuterol & had a 23% increase. Also the fact that my symptoms coincide with low peak flows & exposure to allergens is a big sign. I often will have a full out body allergic reaction, including rashes/hives, allergic rhinitis symptoms& coughing/shortness of breath. I won't do the methacholine b/c they stop the Advair & other allergy meds for toooo long(10 days!).. I would be covered in rashes/hives, very sick from the allergic rhinitis/ETD symptoms, and also coughing and not breathing. I literally can't live without Advair, I stopped it once for a week and I couldn't stop coughing & being short of breath.
So through all this mess, I know it is asthma. I'm trying to find a good asthma/allergy specialist who is knowledgeable in all areas of allergies and asthma, but for right now, my asthma is pretty controlled by my meds.
oh yeah I have heard it can produce false negative results. all tests can, you can repeat it, but no telling it will be right this time or no.
Take care
Linear Mode
