My 13 Y/o Son Was Diagnosed With The Flu Yesterday

My 13 y/o son was diagnosed with the flu yesterday and was prescribed Tamiflu. He took his first dose last night and woke up with red, itchy spots on palms of hands and soles of feet. He also has what appears to be oozing spots on scalp. I called pediatrician and they scheduled appointment for tomorrow. It seems as if the red spots/blushes have spread.