It is unlikely that your son
The LUNG LINE nurses will give you good advice.
Have you considered having a very good ENT (Ear, nose & throat) doc join your son's medical team, to investigate the bulge near his epiglottis? ENT's would most likely know more about this area than Pulmonologists (lung docs).
Also, consider the possibility that GERD may be one of several factors, becaue GERD is very common, including the LPR type (laryngeal-pharyngeal reflux).
I wish the best for your son.
Sincerely, Concerned lady
http://cantbreathesuspectvcd.com (look at page 3 of my website, for more food for thought)