A 45-year-old woman presented to the ED complaining of a dry mouth for a few weeks. Three days earlier, she noticed some painless swelling of the right side of her face. She denies a sore throat, but said she needs to drink a lot of liquid to help swallow food. She wakes in the middle of the night, in fact, needing something to drink.
She has no significant past medical history and takes no medications, and her exam is remarkable only for swelling on the right side of her face. The rest of her head and neck exam are normal except both eyes look irritated.
What is the diagnosis? See p. 11.