Measles, mumps, Rubella and varicella
This is a long one! Get cozy. And if you're motivated, read the article too.
Globally, vaccine rates have fallen and these illnesses, previously uncommon, are making a comeback. This is a review of the etiology, presentations, complications, and possible treatments of each:
Measles: >90% of susceptible contacts will contract the disease with an R-naught of 12-18. It's spread by respiratory droplets and aerosolized particles; it can be infectious on surfaces and in the air for up to 2 hours. There is a profound immune suppression following infection, which often leads to a bacterial superinfection. One dose of the vaccine is 93% effective (97% when the second dose is given). Recommended isloation: 4 days from when rash develops. (not so) Fun facts: in 2000, measles was eliminated in the US. In 2024, there were 285 cases of measles, with 40% requiring hospitalization; in 2025 (through AUGUST), there have been 1431 cases and 2 fatalities. Presentation: the classic cough, coryza and conjunctivitis with high fever, 2-3 days later Koplik spots develop, another 2 days later (4-5 days total) the classic rash develops and spreads from head to toes ("a bucket of Measles Red paint is dumped on their head"); Complications: pneumonia, AOM, encephalitis, diarrhea, blindness; subacute sclerosing panencephalitis in 5-10 patients per 1 million cases and can occur 7-10 years after infection.
Mumps: less infectious than measles (phew). There is only a 30% transmission rate. Spread via respiratory droplets or contact with salivary secretions. Vaccine isnt as good either- 1st dose results in 72% immunity, and 2 brings it up to 86%. This leads to outbreaks being more common, but still only about 350 cases last year. Recommended isolation: 5 days from when parotitis develops. Presentation: viral prodrome, parotitis; up to 1/3 are asymptomatic; Complications: meningitis, cerebellar ataxia, encephalitis, pneumonia, bleeding problems, orchitis/oophoritis, hearing loss/deafness, myocarditis, arthritis, nephritis. Subfertility occurs in 1/8 with orchitis
Rubella: 3-day or German measles; spread via respiratory droplets. Fetuses are at serious risk for devastating consequences due to placental transfer (in 60s, about 20k infants per year with congenital rubella, now only about 10 cases of acquired rubella every year). Strong vaccine- single dose is 97% effective. Recommended isolation: 5-7 days from when rash develops. Presentation: 25-50% are asymptomatic (but still spread infection); flu-like prodrome for 1-5 days (with posterior chain/suboccipital lymphadenitis); macular rash starts on face and lasts 3 days; Complications: leading cause of preventable congenital birth defects; encephalitis, Guillian-Barre syndrome, thrombotic thrombocytopenic purpura and hemolytic anemia
Varicella: spread via respiratory droplets, aerosolization of particles, and direct contact. 2 doses are 90% effective. Recommended isolation: until lesions crust over. Prior to vaccine, about 4 million cases, 12,500 hospitalizations, and 150 deaths/year. Presentation: classic rash, centripetal spread, macule-> papule->vesicle->pustule; up to 500 lesions can be present, in different stages of healing, scab over in about 7 days; doesn't involve palms and soles (to differentiate from HFM); Complications: acute cerebellar ataxia, seizures, meningitis, encephalitis, ADEM, bacterial superinfection; serious complications occur in about 8.5/100k, with neurologic being the most common (~60%)
Treatment: Supportive care for all! With a few caveats...
Bottom Line: There's a reason (or a LOT of reasons) we encourage vaccination against these diseases. They are dangerous, not just to the patient, but to the public, and even to future generations. Furthermore, there isn't a lot we can do once someone is infected. Prevention is the best strategy. Knowledge is power. We need to take the time and educate our vaccine-hesitant families, and keep a high-index of suspicion for these re-emerging diseases.
Globally, vaccine rates have fallen and these illnesses, previously uncommon, are making a comeback. This is a review of the etiology, presentations, complications, and possible treatments of each:
Measles: >90% of susceptible contacts will contract the disease with an R-naught of 12-18. It's spread by respiratory droplets and aerosolized particles; it can be infectious on surfaces and in the air for up to 2 hours. There is a profound immune suppression following infection, which often leads to a bacterial superinfection. One dose of the vaccine is 93% effective (97% when the second dose is given). Recommended isloation: 4 days from when rash develops. (not so) Fun facts: in 2000, measles was eliminated in the US. In 2024, there were 285 cases of measles, with 40% requiring hospitalization; in 2025 (through AUGUST), there have been 1431 cases and 2 fatalities. Presentation: the classic cough, coryza and conjunctivitis with high fever, 2-3 days later Koplik spots develop, another 2 days later (4-5 days total) the classic rash develops and spreads from head to toes ("a bucket of Measles Red paint is dumped on their head"); Complications: pneumonia, AOM, encephalitis, diarrhea, blindness; subacute sclerosing panencephalitis in 5-10 patients per 1 million cases and can occur 7-10 years after infection.
Mumps: less infectious than measles (phew). There is only a 30% transmission rate. Spread via respiratory droplets or contact with salivary secretions. Vaccine isnt as good either- 1st dose results in 72% immunity, and 2 brings it up to 86%. This leads to outbreaks being more common, but still only about 350 cases last year. Recommended isolation: 5 days from when parotitis develops. Presentation: viral prodrome, parotitis; up to 1/3 are asymptomatic; Complications: meningitis, cerebellar ataxia, encephalitis, pneumonia, bleeding problems, orchitis/oophoritis, hearing loss/deafness, myocarditis, arthritis, nephritis. Subfertility occurs in 1/8 with orchitis
Rubella: 3-day or German measles; spread via respiratory droplets. Fetuses are at serious risk for devastating consequences due to placental transfer (in 60s, about 20k infants per year with congenital rubella, now only about 10 cases of acquired rubella every year). Strong vaccine- single dose is 97% effective. Recommended isolation: 5-7 days from when rash develops. Presentation: 25-50% are asymptomatic (but still spread infection); flu-like prodrome for 1-5 days (with posterior chain/suboccipital lymphadenitis); macular rash starts on face and lasts 3 days; Complications: leading cause of preventable congenital birth defects; encephalitis, Guillian-Barre syndrome, thrombotic thrombocytopenic purpura and hemolytic anemia
Varicella: spread via respiratory droplets, aerosolization of particles, and direct contact. 2 doses are 90% effective. Recommended isolation: until lesions crust over. Prior to vaccine, about 4 million cases, 12,500 hospitalizations, and 150 deaths/year. Presentation: classic rash, centripetal spread, macule-> papule->vesicle->pustule; up to 500 lesions can be present, in different stages of healing, scab over in about 7 days; doesn't involve palms and soles (to differentiate from HFM); Complications: acute cerebellar ataxia, seizures, meningitis, encephalitis, ADEM, bacterial superinfection; serious complications occur in about 8.5/100k, with neurologic being the most common (~60%)
Treatment: Supportive care for all! With a few caveats...
- vitamin A in measles can decrease morbitidy/mortality but this comes from studies where patients were likely already deficient; can give vaccine as post-exposure prophylaxis up to 72 hours later, immune globulin if 3-6 days later (dont give IG and vaccine together)
- no post-exposure prophylaxis recommended for mumps or rubella; dont give steroids with mumps orchitis
- antivirals (acyclovir) in varicella for those at risk of severe disease (earlier is better); yes to post-exposure prophylaxis in unimmunized up to 5 days after; immune globulin for those who cant get vaccine
- antibiotics for all with bacterial complications
Bottom Line: There's a reason (or a LOT of reasons) we encourage vaccination against these diseases. They are dangerous, not just to the patient, but to the public, and even to future generations. Furthermore, there isn't a lot we can do once someone is infected. Prevention is the best strategy. Knowledge is power. We need to take the time and educate our vaccine-hesitant families, and keep a high-index of suspicion for these re-emerging diseases.
