question: During the evening, mainly, my back starts to itch terribly. What causes this? I am now sitting at my desk and or an unknown reason, which is strange, my back is now itching. It is because I drink mountain dew sodas? I am a 3rd year doctoral student who works full-time, and take care of two sisters who are ill. I thought it was because of the stress I m dealing with; but need to know how to resolve the itching. Also, I have bumps on my back and top of arm. I m a 59 year old African American female.