Can't Get Full Breath / tightness In Chest

first of all- 15 years old, guy

Okay a little history, I'm currently on advair and singulair to manage my asthma. In the past (up untill this month) this combo of meds has worked fine. I used to use my short acting inhaler about once every two-three weeks.

Aso noteworthy: In the past 2-3 years, I used to stop using the singulair in the late summer through January. In the past year though, I have not stopped using the singulair, at all.

Recently (late July) I went on a trip to New Hampshire, very country-ish (compared to densely populated New Jersey- Not a city however). While on that trip, I experienced no medical difficulties whatsoever.

When I came back to NJ though, I developed severe breathing problems. Occasionally, it gets to the point where I can NOT get that full breath of air, not matter how hard I try. usually, this does not occur. however, it does often interfere with my sleeping, and daily activities. Such as getting very winded after climbing up a flight of stairs.

I have seen a specialist today (mainly to get a skin test to confirm my suspicions about food allergies, and airborne ones. FYI- very allergic to trees, and molds), but in terms of asthma he was pretty much dumbfounded at my condition. first, he gave me a pulmonary function test (i think that's what it's called- it tests your lung capacity), then he gave me two puffs of albutoral, then fifteen minutes later (after the skin test), he gave me the PF test again. There was absolutely no notable difference in the two different times, he said that even if I didn't have an asthma attack, there should of been at least a slight difference.

His idea is to ween me off of the meds, since they seem to have no affect (if anything advair is just an added steroid that could be doing me more harm than good) on my condition. Then see if my condition remains stable, if so, perhaps further diagnose it as something other than asthma.

Oh, and, this feels EXACTLY like when I have an asthma attack

SOOOOO....

My question to you guys is, what could a 15 y/o have that could mimic the symptoms of asthma. I figure i should at least have a list of my own to go through.