Has anyone experienced erythema nodosum? I developed 2 red tender lumps on my shin then added 2 more this week. It took a couple of doctors to figure it out but they have no idea why I got it. They have advised it will go away in 4 to 6 weeks. It's making me anxious as they have no explanation why I got it. Two weeks into radiation treatment and so far so good, just tired all the time.