Roseola

Description

Roseola infantum is a common illness in preschool-aged children with a classic presentation of fever lasting 3 to 7 days followed by rapid defervescence and the appearance of a blanching maculopapular rash.

Epidemiology

• Roseola affects children from 3 months to 4 years of age. The peak age is 7 to 13 months.
• 90% of cases occur in the first 2 years of life.
• No gender predilection
• Roseola can occur throughout the year; outbreaks have occurred in all seasons.

General Prevention

• The virus that causes roseola infantum is usually transmitted via respiratory secretions or fecal–oral spread.
• Good hand hygiene is recommended.
• Outbreaks in hospitals have been reported, and standard infection control precautions are recommended.

Pathophysiology

• Incubation period is 5 to 15 days.
• The typical pattern of rash that appears as the fever disappears may represent virus neutralization in the skin.

Etiology

• The major causes of roseola are human herpesvirus 6 and 7 (HHV-6 and HHV-7).
  • HHV-6 was first associated with roseola infantum in 1988.
  • HHV-6 and HHV-7 account for 20–40% of unexplained febrile illness in emergency department visits by febrile infants 6 months to 2 years of age.
  • Almost all children will acquire a primary infection and be seropositive for HHV-6 by the age of 4 years.
  • ~30% of children infected with HHV-6 will present with the classic manifestations of roseola.
• Roseola-like illnesses have been associated with a number of different viruses, including:
  • Enterovirus (coxsackievirus A and B, echoviruses)
  • Adenoviruses (types 1, 2, 3)
  • Parainfluenza virus
  • Measles vaccine virus