Thank you for waiting. The area that is swollen on Sparky is called the tympanic region.
The most common cause of such swelling is an ear abscess or infection. This is not something that is easy to treat. It will probably require injections of antibiotics, and surgical draining may be necessary.
Less common causes of this type of swelling include vitamin A deficiency and tumors.
You'll need to make an appointment with a reptile vet. I know you would like a home treatment, and I would like to give you one, but infections, abscesses, and tumors all need to be treated by a vet. You don't want to increase the turtle's vitamin A without knowing for certain that's what is wrong, because too much vitamin A can be harmful. This link will take you to a directory of reptile vets:
If you would like me to find a vet for you, please give me your zip code. If you have more questions, just let me know. I hope Sparky will quickly reach a full recovery.
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