Slapped cheek syndrome (erythema infectiosum)
Slapped cheek syndrome is caused by parvovirus B19, and it is known mostly by the way it looks: a child with vividly red cheeks, as though someone had struck…
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Medicines commonly prescribed for Slapped cheek syndrome (erythema infectiosum)
For informational purposes only. Always consult a doctor before using any medicine.
Dosage form: TABLET, 1 g paracetamolActive substance: paracetamolManufacturer: Laboratorios Combix S.L.U.Prescription requiredDosage form: EFFERVESCENT TABLET, 1000 mgActive substance: paracetamolManufacturer: Laboratorio Stada S.L.Prescription requiredDosage form: TABLET, 1 gActive substance: paracetamolManufacturer: Mabo Farma S.A.Prescription required
Slapped cheek syndrome is caused by parvovirus B19, and it is known mostly by the way it looks: a child with vividly red cheeks, as though someone had struck them across the face. It also goes by the name fifth disease, from the old list of childhood rash illnesses, and by its medical name, erythema infectiosum. In children it is mild and settles on its own, and if that were the whole story this page would be half its length. But this harmless infection has three groups of people for whom it is serious: women who are pregnant, people with chronic haemolytic anaemia, and people whose immune system is weakened. They are the reason all of this is written down.
How the illness unfolds
Between catching the virus and the first signs there is a gap of roughly one to two weeks. It begins with nothing distinctive: for a few days the person simply feels unwell.
- a mild temperature;
- a runny nose and a sore throat;
- headache;
- general listlessness, sometimes slight nausea.
Then comes the feature that gave the illness its nickname: both cheeks turn a bright red, as if slapped, while the skin around the mouth stays pale. This lasts a few days.
One to four days later the rash moves lower — onto the trunk, the shoulders, the thighs and the buttocks. Here it looks quite different: pink, lacy, with gaps in it like netting. It can itch a little, particularly on the legs.
Then comes the part that often alarms parents. The rash on the body fades and reappears, over and over, for weeks and occasionally for as long as a month or six weeks. What brings it out is warmth: a hot bath, sunshine, running about, being upset. This is not a relapse and not a complication. By then the child is well and no longer infectious; it is simply that the blood vessels in the skin go on responding this way for a while.
When a person is infectious
This is the least intuitive thing about the illness and worth understanding. The virus spreads through coughs and sneezes, on hands and on objects. A person is infectious during those first few days of runny nose and temperature, when nobody suspects anything. By the time the cheeks turn red, the infectious period is essentially over: the rash is the immune system's answer to the virus, not the height of the infection.
Two practical conclusions follow. First: there is no need to stay at home once the rash has appeared — a child can go to school or nursery and an adult can go to work. Second: containing this infection is close to impossible, because people are at their most contagious precisely when they think they have an ordinary cold.
There is one important exception to that rule. People with a weakened immune system, and those in whom the infection has caused a sudden drop in haemoglobin, stay infectious for a long time — weeks and longer. That is exactly why they are isolated in hospital.
None of this cancels the ordinary measures: wash hands, cough and sneeze into a tissue and bin it straight away. And do tell the school or nursery that your child has slapped cheek syndrome — there may be pregnant staff and other children for whom it matters.
If you are pregnant
Start with the reassuring part. More than half of adults had this infection in childhood, often without noticing, and are immune for life; for them contact is harmless. And even where a pregnant woman does catch it, the great majority of pregnancies carry on entirely as normal.
But the risk is real. The virus can cross to the baby and suppress the production of red blood cells there. Severe anaemia develops and, following it, hydrops fetalis — a build-up of fluid in the baby's tissues and body cavities. This can lead to the loss of the pregnancy. Infection is most dangerous in the first half of pregnancy, up to around twenty weeks; after that the risk is appreciably lower.
What to do:
- Contact the doctor looking after your pregnancy if you have been in contact with someone who has it — even if you feel perfectly well and have no symptoms at all. There is no need to wait for a rash, and this is the single most important instruction on this page.
- The same applies if you develop a rash or joint pain, or simply suspect this infection.
- Your doctor will arrange a blood test for antibodies: it shows whether you have had the infection before, have it now, or have never met the virus.
- If infection is confirmed, the baby is monitored by ultrasound for a period, looking for early signs of anaemia and fluid accumulation. That monitoring is the whole point of getting in touch early: hydrops can be treated, and treated successfully, but only if it is caught.
There is no vaccine against parvovirus B19, and there is little value in avoiding people as a precaution. What there is value in is reporting a contact once it has happened, because everything after that depends on a timely blood test.
Haemolytic anaemia: why this is an emergency
For a few days parvovirus B19 halts the production of red blood cells in the bone marrow. In a healthy person this passes unnoticed: red cells live about four months, and a short pause changes nothing.
But where someone has a chronic haemolytic anaemia — sickle cell disease, thalassaemia, hereditary spherocytosis and other conditions in which red cells are destroyed quickly — the body has to make replacements continuously. Stop that production and the haemoglobin collapses within days. This is called an aplastic crisis, and it is a medical emergency.
The signs not to miss in someone with such an anaemia:
- sudden, unusual pallor — of the skin, the lips, the inner surface of the eyelids;
- severe weakness: a child who is limp and will not play, an adult who cannot manage ordinary tasks;
- breathlessness on the slightest exertion, or at rest;
- a racing heartbeat;
- dizziness, fainting or feeling close to fainting;
- in children, drowsiness that is hard to rouse them from.
With these signs, seek medical help immediately — within the hour, not within the day. If the person is struggling to breathe, loses consciousness or cannot be woken, call an ambulance; across Europe the single emergency number is 112. The condition is treatable, most often with a blood transfusion, after which the bone marrow recovers by itself. What is dangerous here is delay, not the illness.
If you or your child has this kind of anaemia and there has been a contact, tell the doctor in charge of your care in advance, rather than waiting for things to worsen.
If your immune system is weakened
This means people after chemotherapy or an organ transplant, those taking medicines that suppress the immune system, and people with leukaemia, lymphoma or HIV with a low lymphocyte count. Their body cannot produce the antibodies that would end the infection, so it does not resolve on its own.
It also looks different from the childhood illness. The characteristic red cheeks may not appear at all; instead there is a slowly deepening anaemia — pallor, tiredness, breathlessness. The diagnosis is made on a blood test, not on the appearance of the skin.
If you are in this group and know you have been in contact with someone who has it, tell your doctor, even if you feel entirely well. The infection can be treated in this situation, but it has to be found first.
Joint pain in adults
This tends not to get written about, and it is asked about constantly. In adults the infection frequently runs its course with no dramatic red cheeks at all, but with the joints instead. It happens most often in women.
What it looks like: pain and stiffness on both sides symmetrically, in the small joints of the hands, in the wrists, knees and ankles. It is worst in the morning. It starts at roughly the same time as the rash and outlasts everything else — usually weeks, sometimes several months.
The essential thing to know is that this does not damage the joints. Slapped cheek syndrome does not turn into rheumatoid arthritis and leaves nothing behind, even though in the first weeks it resembles it closely enough for the two to be confused. Ordinary over-the-counter painkillers help, along with resting the affected joints; discuss which one to use with a doctor or pharmacist. If the joints hurt for longer than a few months, or if swelling, a different sort of rash or fever join in, see a doctor and have it looked into separately.
What to do at home
There is no treatment aimed at the virus itself, and none is needed: the body deals with it. Antibiotics are useless here, since the infection is viral. What helps:
- rest while there is a temperature and weakness;
- plenty of fluids; babies should carry on with their normal feeds;
- paracetamol or ibuprofen for temperature and aches, if the person is uncomfortable;
- cool air and light clothing — heat brings the rash out more strongly;
- for itching, a cool shower and a moisturiser.
What not to do: children and adolescents should not be given aspirin. And do not try to treat the rash away with creams — it will fade on its own, and rubbing only makes it more obvious.
See a doctor the same day if the temperature persists beyond a few days or returns after an improvement, if a child is listless or refusing to drink, if the rash does not look like the one described above — dark spots, bruising, blisters — or if you are simply not sure this is the illness in question. There are a great many similar rashes in children, and they cannot always be told apart from a description.
Online consultation
A remote appointment settles two questions well. The first is what the rash actually is: the doctor looks at photographs, asks how it began, helps distinguish this infection from other childhood rashes and from allergy, and says whether anything needs doing at all. The second, and the more important, is what to do after a contact if you are pregnant, have a haemolytic anaemia or a weakened immune system: the doctor explains which tests are needed, how soon they should be done and what follows. That is a conversation worth starting straight away, without waiting for symptoms. The signs of an aplastic crisis listed above are not dealt with online — those go to emergency care immediately.
This material is for information only and does not replace medical advice.
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