Measles (Rubeola) Flashcards
What type of virus causes measles?
Measles virus (Rubeola), a paramyxovirus
What type of genetic material does measles virus have?
Single-stranded RNA (ssRNA)
Is measles virus enveloped or non-enveloped?
Enveloped
How is measles transmitted?
Airborne respiratory particles
What is the prodrome of measles?
Fever, malaise, cough, coryza, and conjunctivitis.
Prodromal symptoms include fever and fatigue in addition to cough, coryza, and conjunctivitis. After 2-4 days, patients are often ill-appearing with a classic maculopapular rash that starts on the face and spreads cephalocaudally. The rash is initially erythematous and blanching but may later coalesce and appear non-blanching, hemorrhagic, or dark brown. Some patients develop white, pinpoint lesions (known as Koplik spots) on the buccal mucosa. These lesions appear after the onset of prodromal symptoms and often resolve when the rash appears. Treatment is generally supportive (eg, intravenous fluids, antipyretics); however, vitamin A is indicated in severe cases to reduce complications and mortality.
What is the characteristic oral finding in measles?
Koplik spots (white lesions on the buccal mucosa).
How does the measles rash progress?
Erythematous/brown maculopapular rash that starts at the head and spreads cephalocaudally and centrifugally, sparing the palms and soles.
Does the measles rash involve the palms and soles?
No, it usually spares the palms and soles.
What are common complications of measles?
- Otitis media
- Pneumonia
- Encephalitis
- Subacute sclerosing panencephalitis (SSPE)
What is subacute sclerosing panencephalitis (SSPE)?
A rare, fatal progressive neurologic disease occurring years after measles infection (7–10 years post-infection).
How is measles diagnosed?
Serology (IgM antibodies) or RT-PCR
What is the treatment for measles?
Supportive care and vitamin A supplementation
Why is vitamin A given in measles?
Reduces morbidity and mortality, especially in malnourished children
What is the most effective way to prevent measles?
MMR vaccine (live attenuated)
When is the MMR vaccine given?
First dose at 12-15 months, second dose at 4-6 years
Who should receive post-exposure prophylaxis (PEP) for measles?
- Unvaccinated individuals exposed to measles within 72 hours (MMR vaccine)
- If the exposed patient is pregnant or is a child is less than 6 months give an IM injection of IvIg
- If the exposed child is between 6 months and 11 months, give the MMR vaccine and IvIG 72 hours later
- If the exposed child is older than 1 year they should get the MMR vaccine within 72 hours.
- If the exposed patient is immunocompromised, give the IvIg within 6 days.
- Exposed patients should isolate for 28 days.
- Exposed healthcare workers should get the vaccine if not immune then isolate for 21 days.
What is the isolation recommendation for measles?
Airborne precautions for 4 days after rash onset (longer if immunocompromised)
Why is measles particularly dangerous in developing countries?
Higher rates of malnutrition, vitamin A deficiency, and complications like pneumonia
What other viral exanthems can be confused with measles?
Rubella, Roseola (HHV-6), Parvovirus B19, Scarlet fever
How does rubella rash differ from measles?
Rubella rash is similar but less intense, shorter in duration, and often lacks Koplik spots
How is measles different from Kawasaki disease?
Kawasaki has prolonged fever >5 days, extremity changes, and mucosal involvement
How is measles different from scarlet fever?
Scarlet fever has a sandpaper-like rash, pharyngitis, and pastia lines
How is Roseola different from measles?
Roseola also presents with fever, often without additional prodromal symptoms, followed by a rash after the fever subsides. Outbreaks of these viral infections are common; however, illness is typically mild in otherwise healthy children.
How does Parvovirus differ from measles?
Parvovirus causes erythema infectiosum, which presents with a nonspecific prodrome (eg, fever, cough) followed by a rash (erythematous cheeks, reticular truncal rash) in school-aged children.
