Measles (rubeola) is characterized by the formation of Koplik's spots in the oral cavity. These spots are bluish-white lesions surrounded by a red ring. Mumps cause the enlargement of parotid glands. Serious complications include deafness in children and orchitis (inflammation of testes) in adults. Rubella (german measles) is characterized by flat pink spots on the face that continue to spread to other body parts.
Measles starts as a fever, cough, runny nose, conjunctivitis (pinkeye), and a red, pinpoint rash that starts on the face and spreads to the rest of the body. If the virus infects the lungs, it can cause pneumonia. Measles in older children can lead to inflammation of the brain, called encephalitis, which can cause seizures and brain damage.
The mumps virus usually causes swelling in glands just below the ears, giving the appearance of chipmunk cheeks.
Rubella is also known as German measles. It can cause a mild rash on the face, swelling of glands behind the ears, and in some cases, swelling of the small joints and low-grade fever.