Overview
Measles is a highly contagious yet highly preventable infectious disease caused by a morbillivirus of the paramyxovirus family. It is rarely seen in the developed world due to immunisation programmes.
It is spread via the respiratory tract in nearly all people who come into contact with it. After overcoming an infection, the person develops lifelong immunity.
Measles can be prevented using the measles vaccine. All deaths in England and Wales since 2000 have been in unvaccinated individuals.
Pathophysiology
Measles infects white blood cells in the respiratory tract and then spreads to nearby lymphoid tissue before spreading in the blood to more lung tissue and distal organs including the brain.
Presentation
Measles typically presents with:
- A prodromal phase 10-12 days after contracting the infection that lasts for 2-4 days before the onset of rash:
- Fever, malaise, irritability
- Cough, coryza
- Conjunctivitis – helps differentiate measles from other flu-like illnesses
- Koplik’s spots – usually occur around 1 day before/at the same time as the rash:
- 2-3 mm red spots with white centres – pathognomonic
- Rash – usually lasts around 1 week
- Erythematous and maculopapular before becoming confluent as it progresses
- Usually starts on the ears and face before spreading to the trunk and limbs, reaching the hands and feet last over 3-4 days
- The rash fades after about 5 days
- The rash may be absent in people who are immunocompromised
Investigations
Overview
Diagnosing measles clinically is unreliable, infection must be confirmed with laboratory testing:
- IgM antibodies to measles:
- Confirm the presence of measles
Management
Overview
Treatment is mainly supportive, however, admission may be necessary for severe disease and immunocompromised or pregnant people.
Measles is a notifiable disease and Public Health England must be notified, even before confirming with laboratory tests.
The child should be excluded from school/nursery for at least 4 days after the initial development of the rash or ideally, until full recovery.
Patient Advice
The child should be excluded from school/nursery for at least 4 days after the initial development of the rash or ideally, until full recovery.
Patients should avoid contact with susceptible people, such as those who are not fully immunised (either by vaccination or natural infection), infants, pregnant people, or immunosuppressed people.
Patients should seek urgent medical help if:
- They deteriorate
- They have shortness of breath
- They have uncontrolled fever
- They have neurological features such as convulsions or altered consciousness
Complications
- Otitis media – the most common, up to 9% of cases
- Pneumonia – the most common cause of death, up to 6% of cases
- Encephalitis – up to 0.1% of cases
- Subacute sclerosing panencephalitis (SSPE) – rare, but serious
- Seizures, decline in motor, cognitive, and behavioural function
- Affects 1 in 25,000 people and is more common in children <1 year
- SSPE occurs around 7 years later after exposure and is always fatal
- Diarrhoea and dehydration
- Blindless – due to measles keratoconjunctivitis
- Measles is a leading cause of childhood blindless globally
Prognosis
- Most people make a full recovery with symptomatic management after around 7 days
- All deaths in England and Wales since 2000 have been in unvaccinated individuals.
