What Causes Itching In Arms And Back Followed By Chest Pain?

Hello, I'm a 29 year old African American female. I was diagnosed with Graves Disease in Nov 2009. I'm taking Tapazole. Other then that I'm pretty healthy. Workout regularly. Yesterday I tested positive for strep. Taking amoxicillian. Over the last week and a half I've been really itchy. It started on my arms, then my back, but my hands have been unbearable. Friday and today I had really bad chest pain. Sharp feeling...not burning like heartburn. I took some benedryl for the itching...didn't help. Any suggestions?