What Causes Red, Swollen And Itchy Toe Which Is Spreading?

About 2 months ago i thought i got bit by a spider. The side of my toe was red, swollen and itchy. It also looked like someone pricked my skin a few times with a pin, but just under the surface of the skin. the itching went away but it is still discolored (reddish purpleish) and it has "spread" to the 2 surrounding toes and one toe on the other foot. my doctor said that the blood vessels are swollen but not sure why. She took alot of blood and a urine sample and came up with nothing. I also was not exposed to cold or had an injury