Measles Flashcards
What is Measles?
What causes Measles?
Measles is an acute viral illness caused by a morbillivirus of the paramyxovirus family.
How does Measles present?
Measles presents with:
- Fever
- Malaise
- Coryza
- Conjunctivitis
- Cough
- Rash
The Measles Rash
- What does the rash look like?*
- How does it progress?*
- What are the mucosal findings?*
The rash is erythematous and maculopapular.
It starts at the head and spreads to the trunk and limbs over 3-4 days.
Koplik spots (small red spots with blueish-white centres) may appear on the mucous membranes of the mouth 1-2 days before the rash appears.
Reference: Green Book
Image Source: https://www.nhs.uk/conditions/measles/symptoms/
How does Measles spread?
- What is the mode of transmission?*
- What is the incubation period?*
- When are individuals infectious?*
Measles is spread by airborne or droplet transmission.
The incubation period is about 10 days.
Individuals are infectious from the beginning of the prodromal period to four days after the rash appears.
How is Measles investigated?
Measles-specific IgM and IgG serology.
How is Measles managed?
The mainstay of treatment is supportive care. Medical care includes consideration of Vitamin A and, less commonly, Antiviral Agents:
Vitamin A
Consider in children <2 years, hospitalised patients, those with complications of measles, immunodeficiency, Vitamin A deficiency, impaired intestinal absorption/malnutrition
Antiviral Agents
Ribavirin and interferon are not used routinely.
Source: https://bestpractice.bmj.com/topics/en-gb/217/management-approach
What are the complications of Measles?
Pneumonia
Otitis Media
Encephalitis
- Post-infectious encephalomyelitis* occurs around one week after onset of rash. It is associated with demyelination and thought to have an autoimmune aetiology.
- Acute measles encephalitis (delayed type)* occurs in immunocompromised patients. It is characterised by acute neurological compromise, deterioration of consciousness, seizures, and progressive neurological damage. It may occur without a preceding measles-like illness or exposure to measles several weeks or months previously.
Subacute Sclerosing Panencephalitis (SSPE)
SSPE is a rare, fatal, late complication of measles infection. It is more common in children who develop Measles aged <1 year. Median interval to onset is 7 years.
Reference: https://bestpractice.bmj.com/topics/en-gb/217/prognosis
What is the underlying pathophysiology of Measles?
Day 0: Droplets infect epithelial cells of nose and conjunctivae; virus multiplies and extends to regional lymph nodes
Day 2-3: Primary viraemia occurs with viral replication in epithelial and reticuloendothelial system
Days 5-7: Secondary viraemia occurs
Days 7-11: Prodromal phase in which infection becomes established in skin and other tissues, e.g. respiratory tract, leading to fever, malaise, conjunctivitis, etc.
Day 12: Koplik spots develop
Day 14: Virus can be found in blood, skin, respiratory tract and organs. Measles rash develops.
Day 15-17: Viraemia gradually decreases as the rash coalesces, corresponding with appearance of the antibody.
Measles: Aide Memoire
Symptoms
Do Re Mi Fa So La Ti
Complications
P O S E
Symptoms
Do - downwards spreading rash
Re - respiratory symptoms (cough, coryza)
Mi - mighty temperature
Fa - fatigue
So - sore eyes (conjunctivitis)
La - late encephalitis (SSPE)
Ti - tiny spots in mouth (Koplik spots)
Complications
Pneumonia
Otitis Media
Subacute Sclerosing Panencephalitis
Encephalitis
