by Arlos » Thu Aug 07, 2014 1:07 pm
Vasculitis (according to Google, anyway) is more an auto-immune situation where the body's defenses against disease start attacking the linings of its own blood vessels. The vessels get inflamed and have local breakages. That's what causes his skin to look like that. The inflamed vessels cause the raised parts, while the breakages lead to bleeding under the skin, resulting in bruises, etc. From that picture, it looks like some of the bleeding happened close enough to the surface to cause external bleeding, which results in all the scabs and continued "oozing" as the damaged blood vessels keep leaking.
From what I've read, most of the time it's unclear what causes the situation to start. It could be an infection of some kind (Hepatitis C is mentioned, but I doubt he has that or Jay would've mentioned it), but it could just as easily be an allergic reaction to something. That's what I'd bet in this case, since it started while he was in a foreign country. Probably something there (maybe even a mosquito bite) sent his immune system haywire.
-Arlos