Rosen & Barkin's 5-Minute Emergency Medicine Consult (626 page)

• Highest incidence in 5–9 yr olds
  
• 2/3 of cases occur in children <15 yr.
  
• Doxycycline is used in children due to potential for fatal cases, the relatively low risk of significant dental discoloration with a short course, and adverse effects of chloramphenicol
  

Use chloramphenicol in pregnant patients.

Doxycycline: 100 mg (peds: 2 mg/kg for <45 kg) PO or IV BID for 5–7 days. Patient should generally be treated 2–3 days beyond becoming afebrile.

• Acetaminophen: 500 mg (peds: 10–15 mg/kg/dose) PO q4h; do not exceed 5 doses/24 h or 4 g/24 h
  
• Chloramphenicol: 75 mg/kg/24 h PO or IV q6h for 5–7 days and 48 hr after defervescence
  
• Solu-Medrol: 125 mg (peds: 1–2 mg/kg) IV
  

FOLLOW-UP

Moderate to severe symptoms

• Mild, early disease with early treatment
  
• Notify family because of clustering and potential exposures.
  

Reflective of defined complications

Reflective of ongoing complications

Early treatment based on the clinical presentation and epidemiology is indicated.

• Buckingham SC, Marshall GS, Schutze GE, et al. Clinical and laboratory features, hospital course, and outcome of Rocky Mountain spotted fever in children.
  J Pediatr
  . 2007;150:180–184.
  
• Centers for Disease Control and Prevention. Tickborne rickettsial diseases. Rocky Mountain spotted fever. Available at
  http://www.cdc.gov/ticks/diseases/rocky_mountain_spotted_fever./
  Updated April 30, 2012.
  
• Chapman AS, Bakken JS, Folk SM, et al. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichiosis and anaplasmosis–United States: A practical guide for physicians and other health-care and public health professionals.
  MMWR Recomm Rep
  . 2006;55(RR-4):1–27.
  
• Chen LF, Sexton DJ. What’s new in Rocky Mountain spotted fever?
  Infect Dis Clin North Am
  . 2008;22:415–432.
  
• Masters EJ, Olson GS, Weiner SJ, et al. Rocky Mountain spotted fever: A clinician’s dilemma.
  Arch Intern Med
  . 2003;163:769–774.
  

CODES

082.0 Spotted fevers

BASICS

• Exanthem subitum
  
• Incubation period of 5–15 days
  
• Mode of acquisition unknown:
  
  • Horizontal spread by oral shedding suggested
    
  • It is spread person to person but is not very contagious.
    
  • Human is the only host.
    
• Pathophysiology:
  
  • Complex immune response (cytokines, antibody responses, T-cell reactivity)
    

• Human herpesvirus 6 (HHV-6):
  
  • Large, double-stranded DNA
    
  • Closely related to human cytomegalovirus
    
• Peak incidence at 6–12 mo; 90% occurrence within 1st 2 yr
  
• Highest incidence in late spring and early summer
  

DIAGNOSIS

• Usually self-limited
  
• Diarrhea
  
• Irritability
  
• Rarely causes severe or fatal disseminating diseases:
  
  • Infectious mononucleosis syndrome of hepatitis
    
• Complications
  
  • Febrile seizures in 5–35%
    
  • Aseptic meningitis/encephalopathy
    
  • Thrombocytopenic purpura
    
• Reactivation in immunocompromised individuals. Manifestations are fever, rash, hepatitis, bone marrow suppression, pneumonia, and encephalitis
  

• Most newborns are seropositive for HHV-6 due to transplacental antibodies.
  
• By age 1–2 yr, >90% of infants are seropositive.
  

• Classic history is the onset of sudden, high fever 39.4–41.2°C (103–106°F) commonly followed by defervescence and the appearance of rash
  
• Absence of physical findings:
  
  • Child looks well
    
  • Temperature normalizes in 3–4 days
    
  • Irritability and anorexia may be present
    
  • Bulging fontanelle may be noted
    

• Enlarged lymph nodes
  
• Maculopapular eruption from trunk to arms and neck after temperature normalizes
  
• Rash fades within 3 days.
  
• Erythematous papules in pharynx (Nagayama spots)
  
• Otitis media is common
  
• Cervical and postoccipital lymphadenopathy
  

Clinical diagnosis:

• High fever in well-appearing child
  

• CBC:
  
  • Initial increase in WBC, then normalization with lymphocytosis; WBC may decrease 3–5 days after onset of illness
    
  • Platelets may be decreased
    
• HHV-6 DNA:
  
  • Detected by polymerase chain reaction
    
  • Available at research level
    
  • IgM appears early and declines as IgG is produced
    
  • May be done on blood and CSF
    
• CSF if concern about meningitis
  

• Fever of unknown origin
  
• Scarlet fever:
  
  • “Sandpaper” rash, Pastia lines, and strawberry tongue
    
• Measles (rubeola):
  
  • Koplik spots, cough, coryza, conjunctivitis, and fever
    
• Rocky Mountain spotted fever:
  
  • Rash begins at ankles and wrists.
    
• Rubella:
  
  • Fever after rash
    
• “Fifth disease” (erythema infectiosum)
  
• Dengue fever
  
• Pneumococcal bacteremia
  
• Meningitis, especially with bulging fontanelle
  

TREATMENT

None

ABC management

• Supportive
  
• Antipyretics:
  
  • Acetaminophen
    
  • Ibuprofen
    

• 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
  

FOLLOW-UP

Fever in child who is toxic and does not respond to initial supportive care

Usually, all patients may be discharged. Usually may not return to daycare until rash has resolved

Re-evaluate if persistent fever after 3–4 days

• Child looks well
  
• Antivirals are not recommended in the immunocompetent child.
  
• Febrile seizures need appropriate evaluation.
  

• American Academy of Pediatrics.
  Report of the Committee on Infectious Diseases.
  29th ed. Elk Grove, IL: American Academy of Pediatrics; 2012.
  
• Laina I, Syriopoulou VP, Daikos GL, et al. Febrile seizures and primary human herpesvirus 6 infection.
  Pediatr Neurol
  . 2010;42:28–31.
  
• Leach CT. Human herpesviruses 6 and 7. In: Hutto C, ed.
  Congenital and Perinatal Infections: A Concise Guide to Diagnosis.
  Totowa, NJ: Humana Press; 2006:101–109.
  
• Leach CT. Roseola (human herpesviruses 6 and 7). In: Kliegman R, Behrman R, Jenson H, et al., eds.
  Nelson Textbook of Pediatrics.
  18th ed. Philadelphia, PA: WB Saunders; 2007:1380–1383.
  
• Prober CG. Human herpesvirus 6. In:
  Hot Topics in Infection and Immunity in Children VII. Advances in Experimental Medicine and Biology
  . New York, NY: Springer; 2011:87–90.