question: age 58, height 5'5'',  8stone 10pounds, have bronchiectasis, non smoker, had tb skin test done76 hours ago. result read by pulmonary nurse after 48 hours and it rated negative. problem is that the area is still red, itchy and feels hard under the skin in the red area, not highly raised. question , how long does the site of the test area remain red itchy and hard