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.

Overview

• RNA paramyxovirus
• spread by droplets
• infective from prodrome until 4 days after rash starts
• incubation period = 10-14 days
• The measles vaccine is a live attenuated vaccine

PC

• prodromal phase
  • irritable
  • conjunctivitis
  • fever
• Koplik spots
  • typically develop before the rash
  • white spots ('grain of salt') on the buccal mucosa
• rash
  • starts behind ears then to the whole body
  • discrete maculopapular rash becoming blotchy & confluent
  • desquamation that typically spares the palms and soles may occur after a week
• diarrhoea occurs in around 10% of patients

Investigations

• 1st: measles specific IgM and IgG serology (ELISA) is most sensitive 3-14 days after onset of the rash
• 2nd: measles RNA detection by PCR best for swabs taken 1-3 days after rash onset

Management