hot & spotty #2…

the case.

A 14 year old boy is bought to ED with a 4 day history of fevers. His parents are concerned as this rampant red rash has rapidly spread across his body overnight….

       

He’s had a cough & flu-like symptoms for 2-3 days. His eyes are blood-shot…

[DDET You “spot” something else that gives you the diagnosis ??]

[/DDET]

[DDET What’s the “spot” diagnosis ?]

Measles.

The most common vaccine-preventable cause of death among children.

Epidemiology.

• A highly contagious, endemic viral infection.
  • Single-stranded RNA paramyxovirus.
• Peak incidence: Winter to Spring.
  • Transmission via respiratory droplets.
• Rare in infants < 6-8 months (2* maternal antibodies)
• Incubation period ~ 10 days (post exposure)
• Infectious period:
  • 1-2 days before prodrome
  • ~ 4 days after rash appears.

The Vaccine.

• MMR vaccine. Two-dose schedule.
• Decreased by 99% since vaccine introduction in the 60’s.
  • > 95% immunity required to prevent epidemics.

Clinically.

• Prodrome ~ 3-4 days.
  • High fevers & URTI symptoms.
    • “Cough, coryza & conjunctivitis”
  • Associated malaise, photophobia, eyelid oedema & myalgias.
• Exanthem develops ~ 14 days post-exposure.
  • Centrifugal pattern: central to peripheral.
  • Hairline –> face –> chest –> abdomen –> feet.
  • Reddish-brown, erythematous maculopapular rash –> confluence (morbilliform).
  • May have desquamation during healing phase.
  • Resolves within 6-7 days.
• Koplik spots (seen above).
  • Pathognomonic exanthem.
  • ~1mm white lesions (with bright red base) on buccal mucosa, opposite lower molars.
  • Present 1-2 days prior to rash.

[/DDET]

[DDET Differential Diagnoses to consider…]

• Rubella
• Scarlet Fever
• Enterovirus
• Roseola
• Erythema Infectiosum (“slapped cheek”)
• Kawasaki disease

[/DDET]

[DDET Confirming the diagnosis…]

• Measles IgM.
  • If positive –> confirms disease.
  • Detectable for ~ 1 month after rash onset.
• Viral culture.
  • from nasopharynx, blood or urine.

[/DDET]

[DDET What potential complications should we look out for?]

Meningoencephalitis / Encephalomyelitis.

• 1:1000 cases.
• 40% die or have severe neurologic injury.
• Symptoms:
  • Ataxia, agitation, vomiting & seizures.

Subacute sclerosing panencephalitis.

• a progressive neurodegenerative disorder
• behavioural disturbance, myoclonus, seizures, pyramidal signs…
• Thankfully RARE.
  • ~5:100,000 cases.
• 2-10 years after measles infection.
• Fatal in 1-3 years.

Others.

• Leukopenia
  • < 2000 is a marker of poor prognosis
• Thrombocytopenia
• Jaundice (rare)
• Bronchiolitis
• Pneumonia (+ giant cell pneumonia)
• Croup
• Cervical adenitis
• Myopericarditis

[/DDET]

[DDET Management.]

• Supportive care.
• Vitamin A.
  • Increased morbidity/mortality with Vitamin A deficiency
  • Consider in children 6-24 months (needing admission).

[/DDET]

[DDET More information for health care workers…]

• Isolate all suspected cases as soon as they are identified
• Maintain standard & airborne precautions.
• If staff have no prior immunity, vaccine provides permanent protection & may prevent disease if given within 72 hours of exposure.
  • 0.25mL/kg (max 15mL)
  • Preferable to IG (which can be given up to 6 days post-exposure), as this immunity is temporary.
• All suspected cases MUST be reports to Public Health for contact tracing etc.

[/DDET]

[DDET What about the pregnant Auntie ??]

“Do we need to keep the kids away from her ?” Mum asks…

The short answer is YES !!

Risk to Pregnant Females.

• Exposure can lead to miscarriage, premature labour or stillbirth.
• Consider use of measles immunoglobulin.
  • Does not prevent complications, but may attenuate disease severity.
• Do NOT have MMR vaccine if you are already pregnant.

If in doubt, the auntie should see her GP as soon as possible.

[/DDET]

[DDET References.]

1. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th Edition.
2. Rosenʼs Emergency Medicine. Concepts and Clinical Approach. 7th Edition.
3. PEMsoft “Measles (Rubeola)” via CIAP

[/DDET]