Roseola infantum

Roseola infantum is an infectious disease most commonly caused by human herpesvirus 6 (HHV-6). It occurs most frequently in children between 6 months and 2 years of age. Roseola infantum is characterized by abrupt onset and resolution of high fever lasting approx. three days, followed by the sudden manifestation of a patchy, nonpruritic rash with macules and papules that starts on the trunk and sometimes spreads to the face and extremities. Roseola infantum is diagnosed clinically; laboratory tests are not typically recommended. The course is self-limited, but symptomatic treatment may be considered. Febrile seizures are the most common complication of infection.

• Most frequent in infants and young children ^[1]
• Peak incidence: 6 months to 2 years ^[1]

Epidemiological data refers to the US, unless otherwise specified.

• Pathogen
  • HHV-6 (and in rare cases HHV-7)
  • Humans are the sole hosts.
• Route of transmission: droplet infection (e.g., saliva)
• Incubation period: 5–15 days

References:^[2][3]

Children with roseola infantum usually appear well. Rarely, children present with complications of roseola infantum (e.g., encephalitis). ^[1][4][5]

Prodrome ^[1][5]

• Fever
  • Abrupt onset of high fever, in some patients > 39.5ºC (103ºF)
  • Lasts ∼ 3 days (up to 7 days)
  • Febrile seizures are a potential complication of roseola infantum.
• Cervical and/or occipital lymphadenopathy
• Inflamed tympanic membranes
• Nagayama spots: papular enanthem on the uvula and soft palate ^[6]
• Cough
• Rhinorrhea
• Fussiness and irritability ^[6]
• Gastrointestinal symptoms (e.g., diarrhea)
• Edematous eyelids and conjunctivitis ^[6][7]

More than 75% of HHV-6 infections do not cause roseola infantum; the most common manifestations of HHV-6 infection are fever and rhinorrhea. ^[1]

Exanthem phase ^[1][5]

• Rash typically manifests after sudden resolution of fever
• Lasts 1–2 days ^[6]
• Patchy macular and papular exanthem that:
  • Is rose-pink in color
  • Blanches upon pressure
  • Is nonpruritic (in contrast to drug rash)
  • Originates on the trunk and sometimes spreads to the face and extremities

The alternative names for roseola infantum, “three-day fever” and “exanthem subitum” (from Latin: “subitus” = sudden), reflect the two phases of the disease: three days of high fever followed by a sudden rash. ^[6]

• Usually a clinical diagnosis ^[1][5]
• Consult infectious diseases for consideration of confirmatory studies (e.g., serology, NAAT) in patients with: ^[1][6]
  • Severe complications
  • Immunocompromise

Laboratory studies are not required but (if performed) may show leukopenia, thrombocytopenia, and elevated transaminases. ^[6]

• Other infectious rashes in childhood
• Drug-induced skin reaction
• Bacterial meningitis

The differential diagnoses listed here are not exhaustive.

Roseola infantum is typically a self-limited illness that can be managed with symptomatic treatment as needed. ^[1][5]

• Consider supportive care for pediatric fever (e.g., acetaminophen)
• Manage associated complications of roseola infantum (e.g., treatment of febrile seizures).
• Immunocompromised patients: Consult infectious diseases for consideration of antiviral therapy. ^[1]
• No infection control measures are required for the exanthem of roseola infantum. ^[1]

• Febrile seizures (in up to 15% of cases), usually without sequelae ^[8]
• Hepatitis
• Meningoencephalitis (very rare)

We list the most important complications. The selection is not exhaustive.

• Very good prognosis; self-limiting disease
• The virus persists lifelong in its host, and reactivation of latent virus or reinfection may occur later in life (especially if individuals become immunocompromised)