What Causes Ear Bleeding With Sinus Infection?

My daughter is at college (4 hours away) and has a sinus infection. Started a z-pak. She says she heard her ear pop yesterday and it hurt a lot. She woke up this morning and her ear is bleeding quite a bit. Now she is in a panic. I told her to go to the ER or the 24 hour care center she was at yesterday. What could cause the bleeding?