Runny Nose?

Neptune is a young QP, almost four months old, and starting yesterday I noticed his little nose holes were very visible. Upon further inspection, I found that the feathers around the area were wet and not poofy enough to cover the holes, as usual. I assumed he might have gotten himself wet in his water bowl, but this morning it was the same thing! And now he's sneezing every few minutes.

There is no color to the discharge around his nostrils, his behavior hasn't changed, and he's eating well. I can't seem to find a whole lot of information about the subject online.

I don't know if he's sick or perhaps reacting to something in the air that's irritated him. Has anyone seen something like this?