- Clinical science
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.
- Most frequent in infants and young children
- Peak incidence: 6 months to 2 years
Epidemiological data refers to the US, unless otherwise specified.
- Duration: 3–5 days
- Abrupt onset of high fever, in some cases > 40ºC (104ºF)
- Frequent cause of emergency room visits for febrile illness
- Cervical, postauricular, and/or occipital lymphadenopathy (in ∼ 98% of cases)
- Inflamed tympanic membranes (in ∼ 93% of cases)
- Nagayama spots: papular enanthem on the uvula and soft palate (in ∼ 87% of cases)
- Other possible symptoms:
- Duration: 2–3 days
Characteristic presentation: subsequent sudden decrease in temperature and development of a patchy, maculopapular exanthem
- Rose-pink in color; blanches upon pressure
- Nonpruritic (DDx: drug allergy!)
- Originates on the trunk; → sometimes spreads to the face and extremities
- Duration: 1–2 days
- 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 → reactivation of latent virus or reinfection may occur later in life (especially if individuals become immunocompromised)