"'Curiouser and curiouser', said Alice".

While repotting my Epidendrum the other day I noticed something that looked like small bumps on the leaves, just a few and spread out un-uniformly. There is no yellowing or discolouration of any kind. I am wondering if anyone might be familiar with what this might be. I have not noticed anything similar on any of my other orchids, and I don't have any creepy crawlies (I took a good look through the old media when I was repotting).

Thanks.