Note
My leg is a lot better, but it might be because I kept it elevated most of the day. I went to the hospital vascular lab to have the veins in my legs ultrasonically checked for clots, and I'm pretty sure that turned out okay (they won't tell you, but they will drop hints). I think it's primarily cellulitis, which is a bacterial infection under the skin. When I googled it, one of the headings was "Necrotizing Skin Disorders", which freaked me out. The swelling is way down, but the redness might be bigger. If it's bigger tomorrow, I'll go back to the doctor and see about a different antibiotic. I do think this one is working, though---it's a lot less painful.
If I had to guess, I think I got this during the Upside Down Rogaine about 10 days ago. I had a ton of scratches on my legs, and I just showered when I got home. I probably should have used Betadine. The scratches had a little line of red, which is something I don't usually see.