Roseola Infantum

Roseola infantum (Exanthema subitum) is an acute, benign infection that affects infants and young children, typically between ages 6 months to 3 years. It is typically marked by several days of high fever , followed by a distinctive rash just as the fever breaks.

Roseola affects both sexes equally and occurs year-round, mostly in spring and fall. Overt roseola is the most common exanthem in children under age 2; inapparent roseola (febrile illness without a rash) may affect the rest.

Causes

Human herpesvirus 6 is thought to cause roseola. The mode of transmission may be saliva and, possibly, genital secretions. The incubation period lasts from 10 to 15 days.

Signs and symptoms

The signs and symptoms of roseola include:

• The child develops a high temperature of up to 40ºC (possibly higher), which usually lasts for a few hours, but may last three to five days.
• As the temperature falls, a raised, red rash appears - first on the body and neck, and later on the face, arms and legs.
• The rash lasts from a few hours to one or two days.
• Roseola may also cause a fever without the rash.
• Children with roseola recover fully, usually within a week.

Diagnostic tests 

Roseola is usually diagnosed based on a complete medical history and physical examination of your child. The rash of roseola that follows a high fever is unique, and usually allows for a diagnosis simply on physical examination. In addition, your child's physician may order blood tests to aid in the diagnosis.

Treatment

Because roseola is self-limiting, treatment is supportive and symptomatic: antipyretic medications to lower fever and, if necessary, anticonvulsants to relieve seizures.

Prevention

There is no known way to prevent the spread of roseola. Because the infection usually affects young children but rarely adults, it is thought that a bout of roseola in childhood may provide some lasting immunity to the illness. Repeat cases of roseola may occur, but they are not common.