My mother-in-law has been on Tarceva for approx 2 months (stage 4 lung cancer). She has an EXTREME rash under her arms. It looks like 3rd degree burns, approx 4 inches in diameter under each arm. Its very painful. We are now in the emergency room waiting to see a doctor. Has anyone had this experience with Tarceva? If so, can you offer advice? This is the 3rd doctor she would be seeing to treat this condition. She is fearful they will make her stop taking Tarceva...