Sinusitis due to impact?

Fifteen years ago, I accidentally skied into a rock. I wasn't wearing a helmet. I absorbed quite a lot of the impact with my head. It could have ended really badly! But it didn't. I just got up and brushed the snow off me. But the next day I was ill. And I stayed ill for a while. In the end I sought medical attention, and was diagnosed with sinusitis. And I have always been convinced that the two are causally linked. But I don't know an awful lot about how sinusitis really works.

Not too long ago I was discussing with someone, and I can't remember who, whether indeed there was a causal relationship. They said that sinusitis means a pathogen has ended up in your system, and you can't create a pathogen out of nowhere from impact with a rock. And that is true! But I figured that if you shake someone's head vigourously enough, substances might end up in places where they normally are not. So I would imagine that pathogen just came from somewhere else in my head. It would have stayed there if I would have managed to avoid that rock.

It's not as if I haven't seen any medical professionals in the last 15 years! But I never really thought to ask. But when I found myself standing next to our medical officer, whose day job is paramedic, during a cave rescue training exercise, I saw my chance. And I asked him if indeed it is possible that the impact caused the sinusitis. And he answered it with a wholehearted yes! And he is only one medical professional, and there is no guarantee that there is consensus on this topic, but I still feel vindicated. He even provided two separate possible mechanisms, but I'm afraid I wouldn't be able to reproduce them here. It went a bit quick. But in the days after, I realised I was really glad I had asked someone. So now I'm putting it here! Does anybody else care? I have no idea! But I clearly do…

The hut I spent the first days of my illness in