Roseola (exanthem subitum)
Roseola is a self-limited childhood infection caused by human herpesvirus 6, and less often HHV-7, marked by 3 to 5 days of high fever followed by a maculopapular rash that appears as the fever breaks. The diagnosis is clinical and management is supportive, with febrile-seizure counseling as the main safety issue.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
A classic childhood exanthem driven by high fever that resolves just as the rash appears: roseola infantum (exanthem subitum, "sixth disease") is caused by human herpesvirus 6 (HHV-6), with HHV-7 as a less common cause of the same syndrome.
- Epidemiology
Age concentration in infancy: most cases occur during the first year of life, with the classic window between 6 and 24 months of age; disease is uncommon after age 4 years because most children have seroconverted by then.
- Risk factors
Age under 2 years is the dominant risk factor, reflecting the near-universal timing of primary HHV-6/HHV-7 acquisition.
- Pathophysiology
Primary infection with HHV-6 (occasionally HHV-7) occurs after salivary exposure, with the virus infecting and replicating in lymphocytes and monocytes.
- Clinical features
High fever with minimal other symptoms is the hallmark and establishes the diagnostic pattern: an abrupt-onset fever, frequently above 40°C (104°F), persists for 3 to 5 days (some sources describe 3…
- Differential diagnosis
Measles: prodrome of cough, coryza, conjunctivitis, and Koplik spots precedes a confluent rash that starts on the head and spreads down while fever is still present (fever and rash overlap, unlike roseola).
- Diagnosis
Roseola is a clinical diagnosis established by the characteristic sequence of 3 to 5 days of high, otherwise unexplained fever in a well-appearing infant, followed by a blanching maculopapular rash…
- Management
First, recognize that supportive care is the entire treatment for typical, uncomplicated roseola because the illness is self-limited; no antiviral therapy is used for classic disease in an immunocompetent child.
- Complications
Febrile seizure is the most common complication, driven by the rapid rate of temperature rise; most are simple (generalized, under 15 minutes, no recurrence within 24 hours) with an excellent prognosis and no increase in developmental risk.
- Prognosis
Excellent for typical disease: roseola is self-limited, resolving fully within about a week without sequelae in the vast majority of immunocompetent children.
- Prevention
No vaccine exists for HHV-6 or HHV-7, so prevention relies on general hygiene rather than immunization.
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Erythema infectiosum (fifth disease)
Erythema infectiosum (fifth disease) is the classic biphasic exanthem of parvovirus B19 infection in children, defined by a slapped-cheek facial rash followed by a lacy reticular rash on the extremities and trunk. It is usually clinically diagnosed and self-limited, but the same virus can trigger aplastic crisis in patients with hemolytic disease and fetal hydrops in pregnancy, so recognizing at-risk exposures drives management.
- Measles
Measles (rubeola) is a highly contagious paramyxovirus infection that has re-emerged in the United States because of low vaccination rates, presenting with a prodrome of the 4 C's followed by a cephalocaudal maculopapular rash, confirmed by PCR or IgM, and managed with supportive care plus vitamin A.
- Rubella
Rubella is a mild, droplet-spread togaviral illness in children and adults, notable mainly for its potential to cause severe congenital rubella syndrome when primary infection occurs in an unimmunized pregnant woman. Diagnosis is by rubella-specific IgM/IgG or polymerase chain reaction (PCR), treatment is supportive, and prevention is the measles-mumps-rubella (MMR) vaccine plus preconception immunity screening.
- Hand-foot-and-mouth disease
Hand-foot-and-mouth disease is a coxsackievirus A (most often A16) or enterovirus 71 exanthem of infants and young children producing oral vesicles/ulcers with oval vesicles on the palms and soles. It is a clinical diagnosis managed with supportive care; enterovirus 71 disease carries the highest risk of neurologic and cardiopulmonary complications.
- Mumps
Mumps is a paramyxovirus infection that has re-emerged with declining vaccination rates and classically causes parotitis with fever, headache, and malaise, complicated by orchitis, aseptic meningitis, pancreatitis, or hearing loss. Diagnosis is confirmed by PCR or IgM serology and management is supportive, since prevention through the two-dose MMR vaccine is the only proven control measure.