Poison Ivy/Blood poison?

My father and I were working out in the garden a few days ago, the next day he had a rash on his leg, said it didn't itch but it felt as if he had ran into a wall where the rash was showing. My first thought was poison ivy, because it had the raised yellowish bumps like ivy gives you but it's been about 5 days and now I can see red lines running down his shin toward his ankle. Can anyone tell me what this is, I certainly don't believe it's poison ivy any more. Photo attached.