When it happens · 3 min read
Bright red cheeks
Their cheeks are so red it looks like someone has struck them. It arrived suddenly, they seem largely fine, and a letter has probably come home from nursery.
The reassuring part is the bit nobody explains: by the time you can see this, it is over.
Last updated August 19, 2026
The order of events
First phase, and it looks like nothing special: fever, muscle aches and tiredness. Most people never connect this stage to what follows.
Then the bright red 'slapped cheek' rash, which is the thing that gets noticed and named.
Then, sometimes a few days later, a second rash that looks LACY — spreading to the arms, legs and even the soles of the feet. It may be itchy, and it usually goes after about a week.
And a genuinely odd feature worth knowing so it does not alarm you months later: even after a child is better, the rash can reappear weeks or months on, typically when they are hot — a bath, a run around, a warm day. That is not a relapse and not a reinfection.
The contagious window closes as the rash opens
This is the part that changes what you do. A child is most contagious in the 5 days BEFORE the rash appears. Once the rash is there, they are no longer contagious.
Which means the nursery letter is always retrospective. The exposure happened before anyone knew, and excluding the visibly-rashy child achieves nothing.
AAP is explicit about the practical consequence: when you see a rash caused by parvovirus, your child is no longer contagious. They do not need to stay home for it, assuming they are otherwise well enough to be there.
The pregnancy exception
This is the one situation to act on rather than absorb. Most of the time fifth disease causes no problems in pregnancy — but rarely, if the virus is passed on in the early stages, it can make it hard for the fetus to produce red blood cells, leading to severe anemia and, in some cases, miscarriage.
A pregnant person exposed to it should contact their obstetrician or midwife rather than wait, and may need additional testing.
Note the awkward interaction with the section above: because the contagious window closes before the rash appears, a pregnant woman is typically exposed before anyone knows the child has it. That is not a reason for alarm, and it is a reason to mention the exposure rather than assume it did not count.
When to call about the child
Symptoms getting worse instead of better. Joint swelling. Or looking very pale, which can point to anemia.
Otherwise this is an illness that mostly needs nothing. There is no treatment for the virus itself; the lacy rash may be itchy and that is the only part that usually wants managing.
Common questions
- Can they go to nursery with the rash?
- Yes, if they are otherwise well. Once the rash appears they are no longer contagious — the infectious period was the 5 days before it showed.
- I'm pregnant and my child has it. What do I do?
- Contact your obstetrician or midwife rather than waiting. It usually causes no problems, but early-pregnancy infection can rarely cause severe anemia in the baby and a risk of miscarriage, and additional testing may be advised.
- Why has the rash come back a month later?
- That is a known feature rather than a relapse. The rash can reappear weeks or months after recovery, usually when the child is hot — after a bath, running about, or on a warm day.
- Is there a treatment?
- No treatment for the virus. The lacy second rash can be itchy and that is generally the only part worth managing. Call if things are worsening, joints swell, or they look very pale.
If it's this, not that
Still not sure
This page is the general answer. Yours is a specific child.
The advisor can be. It has read everything here, and it knows how old your children actually are — which is the whole difference wherever guidance changes with age. Ask it anything.
- She's got a temperature of 100. Is that something to worry about?
- He's obsessed with space and galaxies — what toys are worth getting him?
Free. It comes with the note.
It answers from the same cited pages you are reading, and when the question is where to go, from the real clinician, hospital and childcare records behind this site — not a link to go search them yourself. It says so when we have not written about something, and it is not a doctor; for anything urgent it gives you the threshold and tells you to call.
Where this comes from
- Fifth disease (parvovirus B19) — the contagious window, the lacy rash, and pregnancyAAP
- Parvovirus B19 in pregnancyCDC
Every claim on this page traces to one of these. See every source we use →
Written from the sources named above, and it is not a substitute for your own doctor. If something feels wrong to you, that instinct is a good enough reason to call — you know yourself and this family better than any page does.