Rosen & Barkin's 5-Minute Emergency Medicine Consult (627 page)

See Also (Topic, Algorithm, Electronic Media Element)

• Fever, Pediatric
  
• Rash, Pediatric
  
• Seizures, Febrile
  

CODES

• 058.10 Roseola infantum, unspecified
  
• 058.11 Roseola infantum due to human herpesvirus 6
  

BASICS

• Also known as German measles or 3–day measles
  
• Transmission via droplets from respiratory secretions
  
• Moderately contagious:
  
  • Especially during rash eruption and infants with congenital rubella syndrome (CRS)
    
• Up to 50% may be subclinical.
  
• Infants with congenital rubella shed large quantities of virus for several months.
  
• Infectious period 7 days before to 5 days after appearance of rash
  
• Incubation period: 14–21 days
  

• Rubella virus (family:
  Togaviridae
  , genus:
  Rubivirus
  )
  
• Live, attenuated virus vaccine indications:
  
  • All children >12 mo and entering school
    
  • All women of childbearing age
    

DIAGNOSIS

• Acute viral disease
  
• Complications:
  
  • Uncommon, tend to occur more in adults
    
  • CRS: Infected women in 1st trimester (hearing loss, mental retardation, cardiovascular defect, ocular defect)
    
  • Arthritis:
    
    • More common in women (up to 79%)
      
    • Chronic arthritis is rare.
      
    • Begins after 2–3 days of illness
      
    • Knees, wrists, fingers affected
      
  • Hemorrhagic manifestations:
    
    • Secondary to thrombocytopenia
      
    • More common in children
      
  • Neurologic sequelae:
    
    • Encephalitis most common in adults; prognosis usually good
      
    • No causal relationship to autism
      

• Low-grade fever
  
• Malaise
  
• Headache
  
• Upper respiratory tract symptoms
  

• Rash:
  
  • Rash is fainter than measles rash and does not coalesce.
    
  • Red macular rash evolving to pink-red maculopapules with occasional pruritus
    
  • Begins in face with rapid caudal spread
    
  • Completed in 1st day and disappears in 3 days
    
  • May have hemorrhagic manifestations
    
• Lymphadenopathy:
  
  • Postauricular
    
  • Occipital
    
  • Posterior cervical
    

Generally clinical diagnosis

• CBC:
  
  • Decreased WBC, platelets (more common in children)
    
• Urinalysis:
  
  • Hematuria
    
• Reverse transcriptase–polymerase chain reaction
  
• ELISA to detect rubella IgM
  
• Rubella antibody titer:
  
  • Acute and convalescent serum specimens
    
  • Hemagglutination-inhibition test most common
    
  • Rubella specific IgM antibodies using enzyme immunoassay (EIA) commercially available. Detectable 4 days after onset of rash
    
  • Definitive diagnosis in acute infection
    
  • Compare infant with maternal sera for CRS.
    
  • False positives in parvovirus, infectious mononucleosis, rheumatoid factor
    
  • May be useful to check for immunity of pregnant patients with potential exposure.
    
• Pharynx:
  
  • Virus may be isolated from pharynx 1 wk before and until 2 wk after rash onset (valuable epidemiologic tool).
    
• CSF:
  
  • Few WBCs (monocytes) in encephalitis
    

• Lumbar puncture if suspected encephalitis
  
• Arthrocentesis in unexplained arthritis.
  

• Scarlet fever:
  
  • “Sandpaper” rash, Pastia lines, and strawberry tongue
    
• Measles (rubeola):
  
  • Koplik spots, cough, coryza, conjunctivitis, and fever
    
• Roseola infantum:
  
  • Spring and fall
    
• Rocky Mountain spotted fever:
  
  • Rash begins at ankles and wrists.
    
• Rheumatoid arthritis
  

TREATMENT

Use N95 filter mask for potential respiratory transmission.

ABC management

• Symptomatic therapy
  
• Antipyretics and anti-inflammatory agents:
  
  • Acetaminophen
    
  • Ibuprofen
    
• Isolate rubella patients from susceptible persons (e.g., pregnancy).
  
• Vaccine:
  
  • Measles, mumps, and rubella vaccine
    
  • Rubella vaccine is live attenuated virus.
    
  • Indications:
    
    • >12 mo and entry to school
      
    • Susceptible postpubertal females
      
    • High-risk groups (colleges, military, places of employment)
      
    • Unimmunized contacts
      
    • Healthcare workers and women of childbearing age born after 1957
      
    • Nonpregnant women may have arthralgia in up to 25%
      
  • Contraindicated in pregnant women
    
  • Avoid pregnancy for 3 mo after vaccination.
    
  • 1 dose confers probable lifelong protection.
    
  • Common complaints are fever, lymphadenopathy, and arthralgia.
    
• Immunoglobulin:
  
  • Will not prevent viremia but may modify symptoms
    

• Acetaminophen: 500 mg (peds: 15 mg/kg/dose) PO q4h; do not exceed 5 doses/24 h or 4 g/24 h
  
• Ibuprofen: 200–600 mg (peds: 5–10 mg/kg PO q6–8h); suspension 100 mg/5 mL; oral drops 40 mg/mL
  
• Immunoglobulin: 0.5 mL reconstituted vial SC (0.25–0.50 mL/kg)
  

FOLLOW-UP

• CRS
  
• Encephalitis
  

• Most patients may go home.
  
• Inquire regarding vaccination status of family members.
  

• Potential exposure or disease in pregnant women
  
• Complications
  
• CRS-suspected child will need comprehensive evaluation.
  

Pregnant women with suspected rubella or exposure must be followed with titers and counseling should have obstetric consult.

• Current literature does not support a causal relationship between childhood vaccination with thimerosal-containing vaccines and development of autism-spectrum disorders.
  
• Infected individual should be isolated from susceptible (pregnancy, immunocompromised) individual for 7 days.