After suffering a kind of persistent nagging discomfort around my right little toe, I did a bit of investigating. It seemed unlikely considering my overall slim build that I had wide feet, and a measurement confirmed this.
However I then looked at my feet and noticed that my little toe was sitting strangely - it was kind of curled inwards and on its side so that the nail was facing right rather than up. See hideous, disturbing, put-you-off-your-food photo for proof:
Apparently this might be what’s known as a “Tailor’s bunion”. But I can’t find much advice relating to cycling. I have custom-moulded insoles in my shoes from a bike fit, so seems unlikely they’d be the cause of it.
Anyone have a similar thing and managed to deal with it? Like I say, my feet aren’t remotely wide, so I want to avoid changing shoes to ones that might cause other fit problems (and anyway, my left food is wider and I don’t have discomfort there).