Right enlarged tonsil since young. Chronic ebv, allergies and acid reflux. No pain. Causes? Been seen by ENT before and quite a few drs over the years

Tonsil enlarged. If an ENT doctor who can examine you does not know the cause it would be very imprudent to try and make a diagnosis without being able to view your medical records and see you. Find another ENT for a second opinion. Good luck.