Adenoids hypertrophy leads to eustachian tube(tube which connects ear to the nasopharynx) blockage. E.T tube blockade causes Ear drum retraction which is the common cause for earache. You need to get X ray nasopharynx done of your child to evaluate the size of adenoids, if huge can be surgically removed. Read Adenoid hypertrophy.
Next Steps
X ray nasopharynx, ENT Specialist consultation.