Hi, I could have written this post and am so curious if you ever figured out what it was! Same good health profile, same normal test results, same ideas about LPR with no improvement on PPIs. I've had laryngoscopy, endoscopy, chest x-ray, pulmonary function test, many blood tests, etc., and I'm on allergy meds. Thanks for any insight you might have - it's driving me a little nuts, although I'm aware that overall I feel very healthy.