Measles_Flashcards
How common is measles in the developed world today?
Measles is now rarely seen in the developed world following the adoption of immunisation programmes.
What can cause outbreaks of measles despite vaccination programs?
Outbreaks of measles can occur when vaccination rates drop, such as after the MMR controversy of the early 2000s.
What type of virus causes measles?
Measles is caused by an RNA paramyxovirus.
How is measles spread?
Measles is spread by aerosol transmission.
When is a person with measles infectious?
A person with measles is infectious from the prodrome until 4 days after the rash starts.
What is the incubation period for measles?
The incubation period for measles is 10-14 days.
What are the features of the prodromal phase of measles?
The prodromal phase of measles includes irritability, conjunctivitis, fever, and Koplik spots.
What are Koplik spots and when do they typically develop?
Koplik spots are white spots (‘grains of salt’) on the buccal mucosa that typically develop before the rash.
Describe the rash associated with measles.
The rash associated with measles starts behind the ears and then spreads to the whole body. It is a discrete maculopapular rash that becomes blotchy and confluent, and desquamation that typically spares the palms and soles may occur after a week.
What percentage of measles patients experience diarrhoea?
Diarrhoea occurs in around 10% of measles patients.
What investigations can confirm measles?
IgM antibodies can be detected within a few days of rash onset to confirm measles.
What is the primary management approach for measles?
The primary management approach for measles is mainly supportive.
When might admission be considered for a measles patient?
Admission may be considered for immunosuppressed or pregnant patients with measles.
Why is measles a notifiable disease?
Measles is a notifiable disease to inform public health authorities.
What is the most common complication of measles?
The most common complication of measles is otitis media.
What is the most common cause of death from measles?
The most common cause of death from measles is pneumonia.
When does encephalitis typically occur in relation to measles onset?
Encephalitis typically occurs 1-2 weeks following the onset of measles.
What is subacute sclerosing panencephalitis and when might it present?
Subacute sclerosing panencephalitis is a very rare complication that may present 5-10 years following the measles illness.
What other complications can arise from measles?
Other complications of measles include febrile convulsions, keratoconjunctivitis, corneal ulceration, diarrhoea, increased incidence of appendicitis, and myocarditis.
How should contacts of measles cases be managed if they are not immunized?
If a child not immunized against measles comes into contact with measles, MMR should be offered within 72 hours, as vaccine-induced measles antibody develops more rapidly than that following natural infection.
summarise measles
Measles
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
one of the most infectious known viruses
spread by aerosol transmission
infective from prodrome until 4 days after rash starts
incubation period = 10-14 days
Features
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
© Image used on license from DermNet NZ
Koplik spots
Investigations
IgM antibodies can be detected within a few days of rash onset
Management
mainly supportive
admission may be considered in immunosuppressed or pregnant patients
notifiable disease → inform public health
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
© Image used on license from DermNet NZ
The rash typically starts behind the ears and then spreads to the whole body
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
A 4-year-old boy is brought to the emergency surgery with a fever and a blotchy rash. His mother says the rash was initially just behind his ears but is now all over his body. On examination, you also noticed clusters of white lesions on the buccal mucosa. The child has not been vaccinated.
What complication is this child at risk of?
Coronary artery aneurysm
Orchitis
Otitis externa
Pneumonia
Ramsay-Hunt syndrome
Pneumonia
Measles complication - pneumonia
This child has measles. Pneumonia is a complication of measles and is the most common cause of death. It occurs when the measles virus affects the lower respiratory tract epithelium, destroying local immunity within the lungs.
The most common complication of measles is otitis media. Other complications of measles include encephalitis, subacute sclerosing panencephalitis, keratoconjunctivitis, corneal ulceration, diarrhoea, increased incidence of appendicitis, and myocarditis. Rest, fluids, and analgesia are recommended to treat measles.
The local Health Protection Team (HPT) must be informed and school/work avoided for 4 days after the initial development of the rash.
Orchitis is a complication of mumps, along with oophoritis, pancreatitis, and viral meningitis. Mumps presents with swelling of the parotid glands, a high temperature, headache, and general malaise.
Coronary artery aneurysm is a complication of Kawasaki disease, not measles. Kawasaki disease presents with a high temperature, rash, conjunctival injection, red, dry, and cracked hands, feet, and lips, and swollen lymph glands.
Otitis externa is incorrect. Otitis media, not otitis externa, is a complication of measles.
Ramsay-Hunt syndrome is incorrect. This occurs when the varicella-zoster virus affects the facial nerve and is a complication of shingles. It presents with a unilateral painful vesicular rash around the ear and weakness of the muscles supplied by the facial nerve. It is treated with antivirals and steroids.
