I also suspect that POIS might be connected either to migraine, or to a pre-existing chronic inflammation (e.g. eyes, ears, sinuses).
I had migraines as a child (the halo kind), which appeared around the time of developing sexuality (age 11-12). These migraines disappeared, but now I have POIS. Also, sexual activity causes earpain, and I feel there might be a chronic inflammation that's causing trouble.
Anyone else with earpain as part of POIS?