One possibility could be angioedema, which can cause throat swelling as well. Your ENT should consider this disease, and various blood tests, including complement levels as well as a beta-tryptase concentration, would be appropriate for initial evaluation.
A laryngoscopy can also be considered to see if there is any anatomical swelling.
To completely rule out GERD, a 24-hr pH study can be considered. If it was indeed uncontrolled, it may be possible that the inflammation in the esophagus could contribute to your symptoms.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b