It turns out that GH was exposed to whooping cough and that might be what's been causing him all of this congested angst. Because he's been on antibiotics for almost a week, there is no way to test him for it, but the symptoms fit and his doctors think that's probably what he had/has. I called our pediatrician, who says that the babies are protected by their immunizations. So far, I seem to have escaped, but I'm on high alert for any possible signs.
Whooping cough, jeez. It sounds so 1920s. Next thing you know, we'll have mumps. Actually, scratch that: GH had the mumps last year. What's next? Rubella followed by swarms of locusts?