Roseola

Also called Sixth disease, Roseola infantum

Three days of high fever in a baby, then the fever stops and a rash appears. The rash is the reassuring part.

What it is

A common viral infection of babies and toddlers, usually caused by human herpesvirus 6, affecting most children before the age of two.

The pattern is distinctive and worth knowing. **A high fever, often 39 to 40 degrees, for three to five days, in a child who otherwise looks reasonably well; then the fever breaks; and then a rash appears.** The rash arriving as the fever goes is the opposite of most childhood illnesses and is the reassuring feature.

The rash is small pink or red spots, often starting on the trunk and spreading, not itchy, and fading within a day or two.

It is one of the commonest causes of febrile seizures, because the fever rises fast. That is frightening and is usually harmless.

The difficulty is the first three days, when there is a high fever and no rash and no obvious source, which is exactly the situation in which serious infection must be excluded. Roseola is a diagnosis made looking backwards, once the rash appears, and it should never be assumed at the fever stage.

No treatment is needed beyond fluids and fever management, and the child recovers completely.

Signs you might notice

Three to five days of high fever, sometimes with mild cold symptoms, irritability, or swollen glands in the neck.

The child usually feeding and playing reasonably despite the temperature.

Fever ending abruptly.

A rash of small pink or red spots appearing as the fever goes, on the trunk first, spreading to the neck and arms, not itchy, fading within one to two days.

A febrile seizure in some children.

**Do not assume roseola during the fever phase.** 999 or urgent assessment for: a rash that does not fade under a glass; a floppy, drowsy or unrousable child; difficulty breathing; cold hands and feet with a fever; a stiff neck; a bulging fontanelle; a fever in a baby under three months; or a child who looks seriously unwell.

Also: fever lasting more than five days, which is not typical and needs assessment, including for Kawasaki disease.

How it can affect day-to-day life

The three days of high fever with nothing to see is genuinely worrying for parents, and it is right to get an unwell baby checked rather than waiting for a rash to explain it.

The rash appearing as the child improves is the moment parents often ring, when it is actually the point at which they can stop worrying.

Fever management is for comfort rather than to prevent seizures: paracetamol or ibuprofen at the right dose for weight, fluids, and light clothing. Sponging with tepid water is no longer advised.

Febrile seizures with roseola are common; knowing what to do in advance makes them survivable for parents. See febrile seizures.

Nursery exclusion is not needed once the child is well.

Most children have had it by two, and second episodes are uncommon.

The key parental message is about the pattern: if the fever lasts more than five days, or the child looks unwell, or the rash does not fade under a glass, that is not roseola.

Supporting someone well

Get an unwell feverish baby assessed rather than waiting for a rash.

Learn the glass test and use it for any rash with fever.

Manage fever for comfort: paracetamol or ibuprofen at the right dose, fluids, light clothing. Do not sponge with water.

Watch feeding and wet nappies; those are the measures that matter.

Expect the rash as the fever goes, and treat that as reassuring rather than alarming.

Know what to do in a febrile seizure: time it, lie the child on their side, do not restrain, call 999 if over five minutes or if it is the first.

Go back if fever lasts more than five days.

Return to nursery once well; no exclusion is needed.

Where to get help

A GP practice or NHS 111 for a feverish baby.

999 for a non-fading rash, a floppy or drowsy child, breathing difficulty, or a first or prolonged seizure.

Meningitis Now publish the child warning signs, which are worth keeping to hand.