measles, atypical

measles, atypical An altered type of measles that may begin with a mild prodrome of fever, headache, cough, and abdominal pain. In other cases, a sudden onset of high fever, headache, and chest pain occur. The rash appears 1 or 2 days later, often beginning on the limbs. Some patients become severely ill. It occurs in people who were given the old killed-virus measles vaccine between 1963 and 1967, which did not provide complete immunity, or in those who received improperly stored (weakened) live virus vaccine after 1967.