why do i itch internally around my lungs and upper muscles in my back whenever I get a upper respiratory infection?

The itching sensation can be caused by the alveoli (small air sacs) being collapsed due to the infection. When you breathe, the sacs open and cause the itching feeling.

It is good lung hygene to focus the air toward these areas of the lung. You can do this by applying pressure to the area in question with your hand and applying the breath to move against the hand pressure. this will focus the air the the infected area of the lung and speed the healing process.