I Have No Knuckles and I Must Punch!

That's funny, I was sure I had knuckles yesterday...

After a wasp sting yesterday morning, I thought my left hand was doing fine. A little pain, but nothing I couldn't handle. Last night it was starting to swell enough that I felt pressure; this morning my thumb has a one-inch range of motion, and my knuckles have basically disappeared. (The knuckles on the fingers are actually inflating, but you get the idea.) There's also a bit of numbness, too, but I think the swelling is just restricting blood flow or something like that.

Here's a picture of the right hand, for reference.

What's really weird is that if I put my palm on a flat surface, it feels curved. The middle of the palm, usually recessed, is now bulging out; the nerves can't tell the difference, so a table feels a bit like a softball.