10% Otitis media
(make sure you discriminate viral from bacterial pneumonia in this case. Viral pneumonia caused by measles itself will be concomitant with the rash. Bacterial pneumonia caused by co-infection will appear 1-2 days after the rash has gone.)
0.1% Meningoencephalitis
(another nice little division here is in quarters; 50% will be cured and fine after measles meningoencephalitis, 25% will have some kind of neurologic sequele and 25% will die! this is the reason we vaccinate people with the MMR vaccine!)
0.00001% Panencephalitis
(this occurs many years (average 7 years) after measles infection and for most means death, another good reason to vaccinate with the live vaccine unless you are immuno-compromised of course)
Other complications: Diarrhoea (most common), Seizures (as rare as meningitis)
(Measles mickey, a reference to the measles outbreak in Disneyland)