Measles in Adult
Measles is transmitted via respiratory droplets. The incubation period after the measles virus enters the upper respiratory mucosa is about 10 days (range 7-21 days), with the rash typically appearing about 14 days after an exposure. Infected individuals are considered contagious from about 4 days prior to the appearance of the rash through about 4 days after its appearance.
A prodrome characterized by fever (up to 105°F [40.5°C]), coryza (nasal congestion), cough, and conjunctivitis occurs for about 3-4 days followed by the onset of the rash (sometimes immunocompromised individuals do not develop the rash). The coryza, a "barking" cough, and conjunctivitis will increase in severity until the rash reaches its peak. The US Centers for Disease Control and Prevention (CDC) reports that approximately 1 of 10 children with measles will develop otitis media, and up to 1 of 20 will develop pneumonia. Encephalitis is a complication in about 1 of 1000 cases.
Subacute sclerosing panencephalitis (SSPE) is a delayed neurodegenerative disorder occurring approximately 10-11 years after acute infection. This complication is characterized by changes in personality, seizures, and coma and eventuates in death.
Although measles was declared eliminated in the United States in 2000, outbreaks resulting from imported cases continue to occur. Most cases are associated with importation of measles by unvaccinated international travelers resulting in local outbreaks in communities with clusters of unvaccinated individuals. There was a high number of reported measles cases in the United States in 2014, with 667 cases reported to the CDC, largely from underimmunized communities in Ohio. From January through July 2019, however, an even higher number of confirmed cases has been documented: over 1100 cases from 30 states (Alaska, Arizona, California, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Missouri, Nevada, New Hampshire, New Jersey, New Mexico, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, Virginia, and Washington). Refer to the CDC for the latest information on measles cases and outbreaks in the United States.
Related topic: Atypical measles
B05.9 – Measles without complication
14189004 – Measles
- Before the eruption, it is easy to confuse measles with common upper respiratory infections.
- Morbilliform or exanthematous drug eruption
- Other viral exanthems – rubella, roseola, enterovirus, Epstein-Barr virus, parvovirus B19, human herpesvirus 6 (HHV-6), and dengue fever
- Rocky Mountain spotted fever
- Kawasaki disease
- Leukocytoclastic vasculitis
- Graft-versus-host disease
- Meningococcemia, especially with atypical measles
- Gianotti-Crosti syndrome