Dermatology, Infections, Pediatrics, Special Populations
Measles is a highly contagious viral infection caused by the Measles Morbillivirus. Transmission rate is as high as 90% in susceptible exposed individuals.
- Measles, a preventable infectious disease, has seen a resurgence in recent years due to reduced rates of vaccination and transmission from travelers arriving from endemic areas.
- Measles should be suspected in any unvaccinated individual from a measles endemic country presenting with fever, cough, conjunctivitis, diarrhea, and/or rash.
- Confirmatory testing is by serum anti-measles IgM Ab or measles RNA in sputum.
- Supportive management is indicated as there is no specific antiviral treatment.
- Outpatient management is appropriate unless there are risk factors for severe infection: children <12 months, unvaccinated immunocompromised patients, pregnancy.
- Diagnosis is largely clinical, with measles infection divided into 4 stages: incubation, prodrome, exanthem and recovery:
- The incubation period for measles is 6 to 21 days.
- The prodrome period involves the development of fever, tachycardia, malaise, and anorexia, followed by nonpurulent conjunctivitis, cough, and coryza. These symptoms last 2-5 days and intensify in severity leading up to the appearance of the exanthem. 48 hours prior to the development of the exanthem, patients may develop Koplik spots, 1-3 mm white or gray spots with an erythematous base seen on the oral mucosa. These spots slough off as the exanthem begins to appear.
- Measles exanthem: An erythematous morbilliform rash that starts on the face and spreads caudally, often sparing the palms and soles. The rash is initially blanching. Other symptoms include lymphadenopathy, pharyngitis, fever, and/or diarrhea.
- Rare but severe complications of measles infection include measles encephalitis, pneumonitis, perimyocarditis, keratitis, or corneal ulceration. These complications are more common in immunocompromised patients or those <12 months of age.
Figure 1. Koplik spots. https://dermnetnz.org/search.html?q=measles Image accessed from DermNet NZ.
Figure 2. Measles exanthem. https://dermnetnz.org/topics/measles Image accessed from DermNet NZ.
Figure 3. Measles exanthem. https://dermnetnz.org/topics/measles Image accessed from DermNet NZ.
- Bloodwork may show leukopenia and thrombocytopenia and chest X-ray may reveal interstitial pneumonitis.
- Confirmatory testing: anti-measles IgM (serum biomarker), RT-PCR for Measles antigen (sputum sample). See this helpful guide from a laboratory in California on collection and handling details.
- A patient suspected of having measles should be placed under airborne precautions as measles can remain airborne for up to 2 hours.
- Cases should be reported to the BCCDC.
- Treatment is largely supportive with fluids, antipyretics, and treatment of complications or bacterial superinfections as appropriate.
- Although clinical data is limited, ribavirin may be used to prevent/treat severe cases of measles. A dose of 15-20mg/kg/day PO BID (total daily dose 30-40 mg/kg/day) for 1-2 weeks (optimal duration unknown) may be used for patients <12 months old with measles pneumonia and patients ≥ 12 months with severe immunosuppression or those requiring ventilation. Side effects of ribavirin may include a dose-dependent reversible anemia due to myelosuppression and increased RBC oxidative stress, in addition to bradycardia and/or elevated liver transaminases.
- For children, 2 doses of vitamin A may be beneficial in acute or severe cases. A third dose can be given 4-6 weeks later if there are clinical signs/symptoms of vitamin A deficiency.
- <6 months old dose: 50,000 IU.
- 6-11 months old dose: 100,000 IU.
- ≥ 12 months old dose: 200,000 IU.
- Clinical improvement occurs about 48 hours following the emergence of ex-anthem. After 3-4 days, the skin eruption darkens, then fades.
- There may be a persistent cough up to 2 weeks after measles.
- All unvaccinated patients should be encouraged to receive two doses of the MMR vaccine at least 4 weeks apart. Unvaccinated patients exposed to a known case of measles may receive the MMR vaccine or IVIG as post-exposure prophylaxis.
- Patients should be educated on the safety of the MMR vaccine, addressing common myths around vaccine hesitancy.
- MMR is an attenuated live virus vaccine that causes a relatively benign infection in the body with minimal symptoms prior to being eliminated by the immune system.
- Common side effects are a mild truncal rash and mild fever lasting 2-3 days approximately 1-2 weeks post-injection. There may also be temporary joint pain/stiffness in older individuals who are not rubella immune.
- Extremely rare side effects include febrile seizures (4/10,000), thrombocytopenia (ITP – 1/40,000), neck/cheek swelling, and anaphylaxis.
- There is no evidence that the MMR vaccine causes Autism Spectrum Disorder (ASD); the time frame when ASD features begin to manifest coincides with the recommended childhood vaccine schedule.
- Unvaccinated patients exposed to measles may receive their first dose of the MMR vaccine within 3 days for Post Exposure Prophylaxis(PEP). Between 3-6 days, consideration of IVIG (400 mg/kg) for PEP. Avoid administering both IVIG and the MMR vaccine simultaneously, as IVIG reduces the immunogenicity of MMR. Physicians should also be aware that IVIG administration delays the subsequent administration of MMRV by at least 8 months.
Quality Of Evidence?
We are highly confident that the true effect lies close to that of the estimate of the effect. There is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
We consider that the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. There are only a few studies and some have limitations but not major flaws, there are some variations between studies, or the confidence interval of the summary estimate is wide.
When the true effect may be substantially different from the estimate of the effect. The studies have major flaws, there is important variations between studies, of the confidence interval of the summary estimate is very wide.
Ribavirin for management of measles
Ribavirin is a guanine nucleoside analogue that has been established as a treatment for chronic Hepatitis C, however it may be beneficial in the early stages of treating some viral infections. In a randomized control study of 100 patients with measles (confirmed by serum IgM antibody detection), symptom duration and complications were reduced. Group A received ribavirin and supportive management while group B received only supportive therapy at a hospital in Kolkata. There were no deaths in the treatment group, while the control group had a 16% mortality rate, with 8% developing encephalitis and 50% developing pneumonitis. (Effects of ribavirin on measles. Pal, G., J Indian Med Assoc. 2011;109(9):666.)
Vitamin A in the management of acute and/or severe measles in children:
Measles infections can worsen vitamin A deficiency by depleting vitamin A stores and increasing its utilization. This effect is more pronounced in patients with poor nutritional status.
Based on a Cochrane systematic review, two doses of Vitamin A 200,000 IU on consecutive days was associated with a reduction in mortality risk in children under 2 years of age (RR 0.18; 95% CI 0.03 to 0.61) and a reduction in the risk of pneumonia-specific mortality (RR 0.33; 95% CI 0.08 to 0.92). There was also a significant reduction in the incidence of croup (RR 0.53; 95% CI 0.29 to 0.89) but no significant reduction in the incidence of pneumonia (RR 0.92; 95% CI 0.69 to 1.22) or diarrhea (RR 0.80; 95% CI 0.27 to 2.34) with two doses.
There was weaker evidence that vitamin A in a single dose was associated with a reduced risk of mortality among children with measles.
Overall, did not report a significant reduction in the risk of mortality in the Vitamin A group when pooling all studies (both single/double doses) using the random-effects model (RR 0.70; 95% CI 0.42 to 1.15). (Huiming Y, Chaomin W, Meng M. Vitamin A for treating measles in children. Cochrane Database of Systematic Reviews, 2005, (4):CD001479.)
MMR vaccine and immune globulin for post exposure prophylaxis (PEP)
A prospective cohort study on a New York orthodox Jewish community which had a measles outbreak in 2013 demonstrated that both MMRV and PEP are effective at preventing measles infection. They treated unvaccinated exposed patients preferentially with the MMR vaccine if exposure history was <72 hours or with IVIG if exposure time >72hrs but <6 days. 44 contacts received MMR pep and 77 received IG PEP. They found the effectiveness of MMR PEP to be 83.4% (95% confidence interval [CI], 34.4%, 95.8%). Effectiveness of IG PEP was 100% (approximated 95% CI, 56.2%, 99.8%). Overall, contacts who received PEP were less likely to develop disease. This aligns with the current Canadian guidelines that recommend PEP for measles. (Arciuolo, R.J., Jablonski, R.R., Zucker, J.R., Rosen, J.B., 2017. Effectiveness of Measles Vaccination and Immune Globulin Post-Exposure Prophylaxis in an Outbreak Setting—New York City, 2013. Clinical Infectious Diseases 65, 1843–1847.. doi:10.1093/cid/cix639).
MMR vaccine for all unvaccinated patients
The MMR vaccine is recommended for all unvaccinated children older than 12 months of age. A recent Cochrane Systematic Review published in November 2021 of 138 studies with over 23 million children showed that the vaccine was over 95% effective in preventing measles with 1 dose of the vaccine. The systematic review also found that there were no reported cases of MMR leading to autism (2 studies, 1,194,764 children) or encephalitis (2 studies, 1,071,088 children) or any other unwanted side effect. There were very small risks of febrile seizures 2 weeks post vaccination or ITP in vaccinated children. Di Pietrantonj C, Rivetti A, Marchione P, Debalini MG, Demicheli V. Vaccines for measles, mumps, rubella, and varicella in children. Cochrane Database of Systematic Reviews 2021, Issue 11. Art. No.: CD004407.
Vaccines for measles, mumps, rubella, and varicella in children.
Di Pietrantonj C, Rivetti A, Marchione P, Debalini MG, Demicheli V. Cochrane Database of Systematic Reviews 2021, Issue 11. Art. No.: CD004407.
OTHER RELEVANT INFORMATION
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by the BC Emergency Medicine Network and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. The BC Emergency Medicine Network is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. The BC Emergency Medicine Network also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated Dec 10, 2021
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