2 of my cats got their ears eaten alive by bugs this year (it's never happened before
) - could it be some sort of bug bite? I used a natural cream called "Gold Nuggest Gnat Away" (actually for horses but can be used on cats and dogs...
) which protects and soothes.
I imagine keeping it clean and dry plus putting some sort of anti-bacterial/anti-fungal cream on it would help.
Good luck!