Hi, AlisaBeth . . . I did have it when I was about nine years old (I am 52 now).
What I remember of it was the doctor gave me some medication to take (most likely antibiotics) and I was out of school for a week.
The most memorable part of it was like having bronchitis but when you cough, you make sort of an odd sound like the name says, a whoop. In my situation, I also would sometimes throw up whatever I ate after coughing.
I did not have any rash or extremely high fever with it.
I would also be interested to hear of anyone else with experience with it.