Infectious diseases


Last update: 19-01-2024

How else can it be called?

  • Morbilli

  • Red measles

  • English measles

  • ICD-10: B05

What is measles?

Measles is a high contagious infection caused by the measles virus.

The disease primarily affects children and the common symptoms include high fever, cough, conjunctivitis and a characteristic red skin rash.

Vaccination against measles significantly reduces the risk of mortality, especially in children under the age of five, by preventing respiratory complications associated with the disease.

Despite the widespread availability of the MMR vaccine (measles, rubella, mumps), measles outbreaks persist globally, posing a significant threat to unvaccinated children.

The recent surge in measles cases can be attributed to a decline in childhood vaccinations, stemming from pandemic-related isolations during COVID-19 and the impact of anti-vaccine movements.

What is the cause of measles?

Measles is caused by a virus member of the genus Morbillivirus in the Paramyxoviridae family.

How is measles transmitted from person to person?

The infection spreads through the nasal and oral secretions of an infected person, with symptoms typically appearing 8 to 14 days after the incubation period.

Direct contact is not necessary, as the virus remain in the air for up to an hour after the sick person has coughed or sneezed.

Following the initial phase, when contagiousness is high, the measles virus continues to be shed, albeit to a lesser extent, during the first 5 days of the rash period.

Transmission occurs through the air and can lead to epidemics during the winter and spring months, affecting both sexes similarly.

After recovering from the disease, lifelong immunity is acquired. Another way to build immunity is by receiving the measles vaccination.

What are the main symptoms for measles?

Measles develops trough three clinical phases:

  • An initial incubation period with minimal symptoms.
  • An early phase marked by intense redness of the oral and throat mucosa.
  • Profuse ocular, pharyngeal, and nasal discharge.

Subsequently, a skin rash develops in the form of merging and scattered red patches, accompanied by cough, fever, and redness of the ocular conjunctiva.

Initial symptoms include high fever for the first 2 days, which decreases towards the end, only to rise again at the onset of the rash (skin eruption).

Other notable symptoms include:

  • Rhinitis and conjunctivitis accompanied by intense discomfort in bright light, tearing, redness of the conjunctivas, and sometimes purulent ocular secretions.
  • A dry, irritating cough that may lead to croup-like symptoms. The characteristic facial appearance features red eyes and swollen eyelids.
  • In the second stage (third to seventh day), redness develops in the oral mucosa, accompanied by distinctive spots called Koplik's spots on the inner aspect of the lips and cheeks, near the molars. These spots resemble small salt grains that can be removed with a tongue depressor.
  • From the fourth day onward, fever reoccurs, and a maculopapular rash emerges, starting on the face, behind the ears, on the wings of the nose, around the mouth, and on the chin. Within hours, it spreads to the trunk, and the extremities the next day. Notably, it does not affect the palms and soles but induces intense itching.
  • After 2 to 3 days, the spots enlarge and merge, the fever subsides, and the overall condition improves. By the fourth day of the rash period, skin lesions begin to lighten, following the same topographical sequence observed during their onset, and a gradual, fine desquamation of the skin occurs.

How can it be detected?

The clinical picture is very clear, and the most significant thing is that multiple cases emerge simultaneously.

Laboratory studies can be conducted to confirm the presence of the measles virus or antiviral antibodies.

Which is recommended treatment?

Measles does not have a specific treatment. Symptoms should be managed to relieve fever and discomfort. Rest, along with the use of paracetamol, maintaining a humid environment, and minimizing exposure to ambient light due to photophobia (light intolerance), is recommended.

Given the connection between measles and Reye's syndrome, it is advisable to refrain from using acetylsalicylic acid (Aspirin®) as a treatment for fever.

For coughs, a cough suppressant can be administered.

In cases of itchy skin, application of menthol or calamine lotions can provide relief.

What are the prognosis and complications of measles?

The usual timeframe for resolving the condition is around 2 weeks when no complications arise.

Measles complications mainly occur in unvaccinated patients or those with other associated problems.

Measles pneumonia is quite common and occurs in approximately 55% of cases. It is known as Hecht's pneumonia or giant cell pneumonia. It presents as a bronchiolitic-like condition with respiratory distress, creating an environment conductive to secondary infections by other pathogens.

Additional respiratory manifestations include otitis media, mastoiditis, and cases of laryngitis with croup.

Acute post-measles encephalitis, affecting one in every 1,000 cases, results from the direct impact of the virus on the brain. Symptoms manifest during the exanthematous period, featuring seizures, drowsiness, and irritability.

How can I prevent it?

The measles vaccine utilizes attenuated viruses. Vaccination is recommended at 12 months of age, using the triple viral vaccine that provides simultaneous protection against rubella, mumps and measles. Revaccination is advised between 3 and 4 years of age and during puberty.

The vaccine is contraindicated for pregnant women and individuals with immunodeficiency.

Moreover, as with all infectious diseases, isolating the affected individual, wearing masks and practicing proper hand hygiene are effective measures to prevent contagion, especially among those at high-risk.

Medically reviewed by Yolanda Patricia Gómez González Ph.D. on 19-01-2024


  • Principles and Practice of Clinical Virology (5th Ed) 2004, Sibylle Schneider-Schaulies and Volker ter Meulen, ISBN: 0-470-84338-1, Pag. 399.
  • Fitzpatrick’s Dermatology in General Medicine (8th Ed) 2008, Lowell A. Goldsmith, Stephen I. Katz, Barbara A. Gilchrest, Amy S. Paller, David J. Leffell, Klaus Wolff, ISBN: 978-0-07-171755-7, Pag. 2337.
  • Measles. World Health Organization. 9 august 2023. Available on:
  • Nelson Textbook of Pediatrics. Chapter 273 - Measles. ELSEVIER. ISBN: 978-0323529501.

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