I have an 18 yr old daughter, senior in high school with CAH.  Puberty did not affect her immune system at all, but she has had issues going way back with getting every bug that is going around, taking much longer to get over it, much longer than normal recovery from injuries, etc.  Not everyone agrees, but I think it does have something to do with the CAH - at least the longer recuperation period when sick.  Last year she missed so much school that I had to go to the principal and ask for an exemption for her so she could get credit for her classes.  Because she was sick during the last 2 weeks of school and she maintains about a 3.5 GPA they also exempted her from exams.  She loved that!