Roseola: The Rash That Appears After a High Fever

What roseola is and how it unfolds

Roseola, sometimes called sixth disease or exanthem subitum, is caused by human herpesvirus 6 (HHV-6). It is the most common cause of fever-related illness in infants, with 90% of cases occurring in children younger than 2 years 1Ref 1Mullins TB, Daley BJ, Krishnamurthy K (2023).Roseola Infantum.Febrile seizures in 10–15% of roseola cases; 90% of cases in children under 2; rash characteristics and clinical course. The illness typically begins with a sudden, high fever — often reaching 103–104°F — that lasts three to five days. The child may be fussier than usual but can appear surprisingly well given how high the temperature is.

When the fever breaks, a flat or slightly raised pink rash usually appears on the chest and belly, sometimes spreading to the neck, face, and arms. The rash is not itchy in most cases and generally fades within one to three days without peeling or leaving marks 1Ref 1Mullins TB, Daley BJ, Krishnamurthy K (2023).Roseola Infantum.Febrile seizures in 10–15% of roseola cases; 90% of cases in children under 2; rash characteristics and clinical course.

How roseola spreads

Roseola spreads through saliva and respiratory droplets — shared cups, coughs, or close face-to-face contact. A child is most contagious during the fever phase, before the rash appears, which makes prevention difficult because the illness is not yet recognizable 2Ref 2American Academy of Pediatrics (2023).Human Herpes Virus 6 (Roseola).Roseola age group (6–24 months), fever pattern, contagion via respiratory secretions, supportive care and return-to-school guidance.

Once the rash appears, children are generally considered to be past the most contagious period. There is no specific isolation requirement once a child is fever-free and feeling well, though guidelines can vary by childcare setting 2Ref 2American Academy of Pediatrics (2023).Human Herpes Virus 6 (Roseola).Roseola age group (6–24 months), fever pattern, contagion via respiratory secretions, supportive care and return-to-school guidance.

Febrile seizures and roseola

The high fever associated with roseola can trigger a febrile seizure — a brief, generalized shaking episode caused by a rapid rise in body temperature. Febrile seizures occur in approximately 10–15% of children during the fever phase of roseola, making roseola one of the most common infectious causes of febrile seizures in young children 1Ref 1Mullins TB, Daley BJ, Krishnamurthy K (2023).Roseola Infantum.Febrile seizures in 10–15% of roseola cases; 90% of cases in children under 2; rash characteristics and clinical course.

Febrile seizures are more frightening to witness than they are medically dangerous in most healthy children, but any seizure warrants a call to your child's care team or an emergency visit, particularly if it is the child's first. A febrile seizure typically lasts less than five minutes and stops on its own. A seizure lasting longer than five minutes is a medical emergency.

Care at home during the fever phase

There is no antiviral treatment for roseola in healthy children. The focus is on keeping the child comfortable during the fever days: offering fluids frequently to prevent dehydration, dressing them lightly, and using acetaminophen or ibuprofen (for children old enough per product labeling) for fever discomfort. Ibuprofen is generally not recommended for infants under 6 months 2Ref 2American Academy of Pediatrics (2023).Human Herpes Virus 6 (Roseola).Roseola age group (6–24 months), fever pattern, contagion via respiratory secretions, supportive care and return-to-school guidance.

Once the fever breaks and the rash appears, most children feel much better. The rash requires no treatment. Children may return to childcare or school once they have been fever-free for at least 24 hours and feel well enough to participate.

When the rash looks different than expected

The roseola rash is characteristically pink, flat or slightly raised, and non-itchy, appearing after the fever lifts. Contact a healthcare provider promptly if:

• The rash appears while the fever is still present
• The rash looks purple or does not fade (blanch) when pressed firmly with a finger
• The child has difficulty breathing, a stiff neck, or seems very unwell despite the fever resolving

A rash that does not blanch can signal a different and more serious condition that requires immediate evaluation 2Ref 2American Academy of Pediatrics (2023).Human Herpes Virus 6 (Roseola).Roseola age group (6–24 months), fever pattern, contagion via respiratory secretions, supportive care and return-to-school guidance.