It could be part of a feather caught in a nare...about three years ago my patty was playing with a down feather from my parrotlet & she was wheezing...took her to the vet & he pulled this really small down feather out...the vet told me he'd seen macaws with small seed hulls in their nares, so I guess it is more common than you'd expect.....
Anyway, I hope that's all it is.....