What should a child do if their ears hurt when flying on an airplane?

Patient's question:

Patient Age: Five years
Condition Description: On October 1, 2009, the patient flew on an airplane, experienced ear pain, and a check-up revealed no issues. They were advised to blow up balloons. Now, the pain occasionally returns.
Previous Treatment and Effect: Blowing up balloons was recommended, and the patient did so for several days but did not persist.
Desired Help: Should the patient visit a large hospital for further examination? If everything is fine, what methods can be used to alleviate the pain? Thank you.

Doctor's answer:

Analysis of the condition: The so-called "airplane ear" is actually Meniere's syndrome, with retraction of the eardrum. Closing the mouth and blowing air can alleviate it somewhat. Meniere's disease is an inner ear disorder characterized by the accumulation of fluid in the membranous labyrinth. The primary clinical manifestations of this condition include sudden vertigo, tinnitus, hearing loss, or nystagmus. Vertigo has distinct episodes and intervals.
Suggestions: Intravenous fluid is one treatment option. Clinical evidence shows that it can relieve symptoms in some patients, while it is ineffective for most. Adding diuretic medications to the fluids can improve the effectiveness, as intravenous fluids can alleviate vertigo symptoms. They can temporarily reduce the pressure of labyrinthine lymph circulation in the balance organs, so intravenous fluids serve as a symptomatic treatment.