What's the plural form of labyrinthitis? Here's the word you're looking for.
Answer
The noun labyrinthitis can be countable or uncountable.
In more general, commonly used, contexts, the plural form will be labyrinthites.
However, in more specific contexts, the plural form can also be labyrinthitides e.g. in reference to various types of labyrinthitides
or a collection of labyrinthitides.