The nose rope is an area where i also find all sorts of gunk and grime. If the nose rope is deep, this is fairly common. I wipe with a soft Kleenex, some times will add witch hazel to it. If you don't notice a smell it's likely not a yeast infection and just some dirt that got caught in there. I know some folks here also use Duoxo pads for the nose rope and skin folds.