Roseola infantum (exanthem subitum, three-day fever) is a viral exanthematous infection caused by the human herpes virus 6 (HHV-6; in rare cases, HHV-7) that mainly affects infants and toddlers. Infection is characterized by high fever, which ends abruptly after three to five days, followed by the sudden appearance of a maculopapular rash. The rash generally appears mainly on the trunk, but sometimes spreads to the face and extremities, and fades within two days. Roseola infantum is a self-limiting condition that is only treated symptomatically. Febrile seizures are a possible complication of infection; however, most patients recover from these seizures without any adverse outcome.
Epidemiological data refers to the US, unless otherwise specified.
- Route of transmission: droplet infection (e.g., saliva)
- Incubation period: 5–15 days
- Duration: 3–5 days
- Cervical, postauricular, and/or occipital lymphadenopathy
- Inflamed tympanic membranes
- Nagayama spots: papular enanthem on the uvula and soft palate
- Other possible symptoms:
- Duration: 1–3 days
- Characteristic presentation: subsequent sudden decrease in temperature and development of a patchy, maculopapular exanthem
- Rose-pink in color; blanches upon pressure
- Nonpruritic (in contrast to the drug allergy rash)
- Originates on the trunk; ; sometimes spreads to the face and extremities
The names of the disease reflect its two phases: Three-day fever refers to 3 days of high fever; exanthem subitum (from Latin: "subitus" = sudden) describes a "sudden exanthem" (upon fever cessation).
- Usually a clinical diagnosis
- Laboratory tests
- Drug reactions
The differential diagnoses listed here are not exhaustive.
- (in up to 15% of cases), usually without sequelae
- 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)