Introduction

Measles is now rarely seen in the developed world following the adoption of immunisation programmes. Outbreaks are occasionally seen, particularly when vaccinations rates drop, for example after the MMR controversy of the early 2000s.

Epidemiology

  • Incidence: 1.50 cases per 100,000 person-years
  • Most commonly see in infants
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Pathophysiology

Overview
  • RNA paramyxovirus
  • spread by droplets
  • infective from prodrome until 4 days after rash starts
  • incubation period = 10-14 days

Clinical features

Features
  • prodrome: irritable, conjunctivitis, fever
  • Koplik spots (before rash): white spots ('grain of salt') on buccal mucosa
  • rash: starts behind ears then to whole body, discrete maculopapular rash becoming blotchy & confluent

© Image used on license from DermNet NZ
Koplik spots

© Image used on license from DermNet NZ
The rash typically starts behind the ears and then spreads to the whole body

Investigations

Investigations
  • IgM antibodies can be detected within a few days of rash onset

Management

Management
  • mainly supportive
  • admission may be considered in immunosuppressed or pregnant patients
  • notifiable disease → inform public health

Management of contacts
  • if a child not immunized against measles comes into contact with measles then MMR should be offered (vaccine-induced measles antibody develops more rapidly than that following natural infection)
  • this should be given within 72 hours

Complications

Complications
  • otitis media: the most common complication
  • pneumonia: the most common cause of death
  • encephalitis: typically occurs 1-2 weeks following the onset of the illness)
  • subacute sclerosing panencephalitis: very rare, may present 5-10 years following the illness
  • febrile convulsions
  • keratoconjunctivitis, corneal ulceration
  • diarrhoea
  • increased incidence of appendicitis
  • myocarditis