Roseola in Babies: Fever Nights, Then the Rash
Roseola is a common viral illness in babies and young toddlers that brings a sudden high fever for about three to five days, then a pink, splotchy rash just as the fever goes away. The AAP says the fever is often between 102°F and 105°F, and that most children with roseola “do not seem very sick.” The rash usually isn’t itchy and fades on its own. The hard part is the fever nights, before anyone knows it’s roseola. Dress her lightly, keep offering milk, and don’t wake her just to give fever medicine. Call the pediatrician for any fever in a baby under 3 months, a fever over 104°F that keeps coming back, a fever lasting more than a day in a baby under 2, or a baby who is very hard to wake.
What roseola week looks like
Roseola usually shows up between about 6 months and 2 years, and the AAP says almost all children catch it in their first two years. It’s caused by a virus, most often human herpesvirus 6. It runs in two clear halves.
The fever days. The AAP describes high fevers lasting 3 to 5 days. The NHS puts the early phase at 3 to 7 days and lists cold-like symptoms, a smaller appetite, swollen eyelids and swollen glands in the neck. The AAP adds that some babies get fussy, or have a runny nose, cough, vomiting or diarrhea. Even so, the AAP says most stay active and playful.
The rash days. As the fever ends, a pink or red rash appears on the chest, stomach and back, then spreads to the neck, arms and legs. Seattle Children’s says it starts 12 to 24 hours after the fever goes away and lasts 1 to 3 days, and that “by the time the rash appears, the child feels fine.” On darker skin, the AAP says it can be harder to see and may look faint red or purple.
Here’s the catch. KidsHealth explains that roseola is often uncertain until the fever drops and the rash appears. During the fever nights, you’re caring for a baby with a high fever and no explanation, so the fever rules below matter more than the name.
The nights in between
Don’t wake her for a dose. Seattle Children’s says not to wake your child to give fever medicine. Whether to give a fever reducer at all, which one and how much is a question for her pediatrician. Ask before the first night if you can.
Dress her lightly. Seattle Children’s warns that too many clothes or bundling can raise body temperature, and the NHS says not to cover a child with too many clothes or bedclothes. The NIH’s Safe to Sleep campaign says overheated babies are at higher risk for SIDS. Light pajamas, no extra blankets.
Keep the milk coming. The AAP says to encourage fluids even if she isn’t hungry. KidsHealth suggests breast milk or formula, and asking about oral rehydration solution. The NHS says to keep breastfeeding as normal. Keep a rough count of wet diapers so you’d notice if they dropped off.
Check on her during the night. The NHS advice for a feverish child includes checking on them regularly, including overnight. You don’t need a reading every hour. Her breathing, color and how she rouses tell you more.
Skip cold baths and sponging. Seattle Children’s says not to use rubbing alcohol or ice water. KidsHealth says there’s no proof lukewarm sponge baths bring a fever down, and they can make a child uncomfortable.
Safe sleep doesn’t change. Back to sleep, on a firm, flat surface with only a fitted sheet, as the NIH describes it. If she’s also congested, baby sleep with a cold covers what’s safe at night.
A thermometer that suits the night. The AAP says a digital thermometer is best, and that rectal readings are the most accurate, especially for babies under 3 months. A forehead (temporal artery) thermometer like the Exergen TAT-2000C+ is the next most accurate and can be used at any age, per the AAP. Ask your pediatrician which reading they want from you.
Febrile seizures: what to know before night one
A fever that climbs fast can trigger a febrile seizure. KidsHealth says this happens in about 10% to 15% of young children with roseola.
The AAP describes what it looks like. Your child may look strange for a few moments, then stiffen, twitch and roll their eyes. They may not respond for a short time, or their breathing or skin color may change. Most febrile seizures last less than one or two minutes.
If it happens, the AAP says:
- Place her on the floor or a bed, away from hard or sharp objects.
- Turn her head to the side so saliva or vomit can drain.
- Put nothing in her mouth.
- Call 911 if the seizure hasn’t stopped after 5 minutes.
KidsHealth’s roseola advice is to get emergency care right away if your child has a seizure, and the NHS says a first febrile seizure needs immediate medical help as a precaution. So for a first one, call 911 even if it stops quickly.
The AAP says most febrile seizures are short and don’t cause brain damage or lasting problems. Fever medicine can lower a fever but doesn’t prevent febrile seizures. If one happens, it isn’t because you missed a dose.
When to call the pediatrician
During the fever days, use the ordinary fever rules. With a fever lasting three to five days, you’ll probably talk to her pediatrician at least once, and that’s how it should go.
| What’s happening | What to do |
|---|---|
| Under 3 months with a temperature of 100.4°F or higher | Call right away (AAP) |
| Fever that rises above 104°F repeatedly | Call right away (AAP) |
| Fever lasting more than 24 hours in a child under 2 | Call (AAP) |
| Very sleepy and not easily awakened | Call right away (AAP) |
| Not drinking, and few wet diapers | Call (AAP) |
| Rash turns into blisters or sores, or is on the lips or inside the mouth | Call (AAP) |
| A soft spot that bulges | Call, and see below |
| Fever comes back after the rash, or the rash gets worse | Call within 24 hours (Seattle Children’s) |
| Rash lasting more than 4 days | Call during office hours (Seattle Children’s) |
| A seizure | Emergency care (KidsHealth); 911 if over 5 minutes (AAP) |
| Rash turns purple or blood-colored with a fever | Call 911 (Seattle Children’s) |
| Trouble breathing, a rash that doesn’t fade under a glass, or blue, gray or blotchy skin | Call 911 (NHS lists these as emergencies) |
Cincinnati Children’s lists a bulging soft spot among the things that can happen during roseola’s fever. Don’t try to judge that one yourself at night. Our guide to your baby’s soft spot explains which bulges are ordinary and which need a same-day call.
For a deeper reference, Betteroo has a day-by-day table and a measles comparison that lines up with the AAP’s advice.
After the rash: getting sleep back
Once the rash shows up, she’s usually over the worst. Her sleep may not bounce back the same night, though, after a few nights of being held, fed and checked. Go back to your usual routine once she’s well. Betteroo’s notes on easing naps and bedtime back after an illness are useful here.
She can usually go back to daycare before the rash fades. The AAP says once she has gone 24 hours without a fever, she can return even if the rash is still there.
FAQ: roseola in babies
How long does roseola last?
About a week in total. The AAP says the fever lasts 3 to 5 days and the rash 1 to 4 days. The NHS says most children recover within a week.
Is roseola contagious?
Yes. The AAP says it spreads through coughing and sneezing. The NHS says it’s thought to be most contagious while the fever is high, so keep her home during the fever.
Should I wake my baby to give fever medicine?
No. Seattle Children’s says not to wake a child to give fever medicine. Ask her pediatrician whether she needs it and how much.
Can roseola cause a seizure?
Sometimes. The fast-rising fever can trigger a febrile seizure. These are usually short and harmless, but a first one needs emergency care. Call 911 for any seizure lasting 5 minutes or more.
