Measles (Rubeola) is a highly infectious disease that is caused by the measles virus. There are two phases of disease: a catarrhal (prodromal) stage and an exanthem stage. The catarrhal stage is characterized by a fever with conjunctivitis, coryza, cough, and pathognomonic Koplik spots on the buccal mucosa. The sudden development of a high fever, malaise, and exanthem represents the next phase. The exanthem stage is typically characterized by an erythematous maculopapular rash that originates behind the ears and spreads to the rest of the body towards the feet. Infection is usually self-limiting and followed by lifelong immunity. Disease management includes vitamin A supplementation, symptomatic treatment, and possible post-exposure prophylaxis (PEP). Measles causes transient immunosuppression and may lead to serious complications such as encephalitis, otitis, or pneumonia. A rare but lethal late complication of measles is subacute sclerosing panencephalitis (SSPE), which may also affect immunocompetent individuals. The prognosis is good in uncomplicated cases. However, newborns and immunocompromised patients are more likely to suffer from severe complications.
The measles vaccine is a combination vaccine that protects against measles, mumps, and rubella (MMR vaccine); the MMRV vaccine also protects against varicella. Immunization is recommended for all children, in addition to adults without evidence of immunity to measles, mumps, and/or rubella.
- Distribution: Measles typically occurs in regions with low vaccination rates and in resource-limited countries. 
- Peak incidence: < 12 months of age 
- ∼ 90%
- Highly contagious 4 days before and up to 4 days after the onset of exanthem. .
- Risk factors for measles, mumps, and/or rubella: The following individuals are at increased risk of acquiring or transmitting measles, mumps, and/or rubella. 
Epidemiological data refers to the US, unless otherwise specified.
- Duration: ∼ 2 weeks after infection
Prodromal stage (catarrhal stage) 
- Duration: ∼ 4–7 days
Exanthem stage 
- Duration: ∼ 7 days (develops 1–2 days after enanthem)
- High fever, malaise
- Generalized lymphadenopathy
Erythematous maculopapular, blanching, partially confluent exanthem
- Begins behind the ears along the hairline
- Disseminates to the rest of the body towards the feet (palm and sole involvement is rare)
- Fades after ∼ 5 days of onset, leaving a brown discoloration and desquamation in severely affected areas
The cough may persist for another week and may be the last remaining symptom.
The most important findings of measles are the 3 Cs and 1 K: Coryza, Cough, Conjunctivitis, and Koplik spots.
Measles should be suspected in a patient with typical clinical findings. Laboratory tests are always necessary to confirm the diagnosis. 
- CBC: ↓ leukocytes, ↓ platelets
- Identification of pathogen: direct virus detection via reverse-transcriptase polymerase chain reaction (RT-PCR) possible
- Biopsy: affected lymph nodes show paracortical hyperplasia and Warthin-Finkeldey cells (multinucleated giant cells formed by lymphocytic fusion).
- Symptomatic treatment 
- Vitamin A supplementation reduces morbidity and mortality (especially in malnourished children). 
- Isolate patients with confirmed infection. 
- All patients: Isolate for 4 days from the onset of rash (longer if immunocompromised).
- Hospitalized patients: Initiate .
- Measles is a nationally notifiable disease; report all cases to the appropriate health departments within 24 hours. 
- See “Prevention” for postexposure prophylaxis for exposed individuals.
Subacute sclerosing panencephalitis (SSPE) 
- Definition: a lethal, generalized, demyelinating inflammation of the brain caused by persistent measles virus infection 
- Primarily affects males between 8 and 11 years of age
- Usually develops ≥ 7 years after measles infection
- Clinical presentation: characterized by four clinical stages
- Prognosis: SSPE leads to death within 1–3 years of diagnosis) 
Other complications 
- Bacterial superinfection
- Frequency: ∼ 1:1000 
- Develops within days of infection
- Acute disseminated encephalomyelitis may develop within weeks.
- Giant cell pneumonia (viral, most commonly seen in immunosuppressed individuals)
We list the most important complications. The selection is not exhaustive.
Available options: live attenuated vaccines that contain multiple antigens
- Measles, mumps, rubella vaccine (MMR)
- Measles, mumps, rubella, varicella vaccine (MMRV)
- Indications and schedule: See “ACIP immunization schedule” for details.
- Contraindications 
- Precautions 
Evidence of immunity 
Indications to test for immunity to measles, mumps, and rubella 
- Pregnant individuals as part of routine prenatal care 
- Immunosuppressed individuals (e.g., individuals with HIV) 
- Undervaccinated individuals with:
- Inadequate or unknown vaccination status in
Evidence of immunity to measles, mumps, and/or rubella
Any of the following constitutes as evidence of immunity:
- Being born before 1957 (not valid for health care personnel or, for rubella immunity, pregnant individuals)
- Confirmed receipt of MMR vaccine and/or MMRV vaccine 
- Laboratory evidence of either: 
The MMR vaccine is contraindicated during pregnancy. Individuals without evidence of immunity to MMR should receive one dose of MMR after delivery, preferably before discharge from the health care facility. 
Individuals with HIV and CD4 percentage ≥ 15% and CD4 count ≥ 200 cells/mm3 for ≥ 6 months and no evidence of immunity to MMR should receive a 2-dose series of the MMR vaccine, administered ≥ 4 weeks apart. Live vaccines are contraindicated in individuals with severe immunocompromise (i.e., CD4 percentage < 15% and CD4 count < 200 cells/mm3).