The rash of CMV is less dramatic and is not associated with the classic prodrome of cough, coryza, and conjunctivitis or Koplik spots seen in measles.
The rash of mononucleosis is not typically associated with the 3 C's (cough, coryza, conjunctivitis) and lacks Koplik spots.
Enteroviral exanthems are very variable and can be morbilliform, but they usually lack the high fever, prodrome, and Koplik spots of measles.
The rash of acute retroviral syndrome is morbilliform but is often accompanied by painful mucosal ulcers, which are not a feature of measles.
While causing fever and rash, Kawasaki is distinguished by its other criteria: conjunctivitis, oral changes (strawberry tongue), peripheral extremity changes, and cervical lymphadenopathy.
Parvovirus B19 causes erythema infectiosum, distinguished by the "slapped cheek" facial rash followed by a lacy, reticular rash on the body.
The rubella rash is a finer, pinker eruption that spreads more quickly and is associated with prominent post-auricular lymphadenopathy, unlike measles.
