Slapped cheek syndrome is a common childhood viral infection. However, it can affect people of all ages. The most common symptom of slapped cheek syndrome is the appearance of a bright red rash on both cheeks (hence the name). Slapped cheek syndrome is cause by a virus called parvovirus B19.

Slapped cheek syndrome is also sometimes known as:

• fifth disease, and
• erythema infectiosum.

How common is slapped cheek syndrome?

Slapped cheek syndrome is thought to be very common. Most people do not realise that they have been infected by the parvovirus B19 virus because it often causes very mild symptoms that are similar to a cold, or no symptoms at all.

It is estimated that 50-80 per cent of all adults have been infected by parvovirus 19. Once you are infected, your body will develop life-long immunity against further infection.

Slapped cheek syndrome usually affects children who are between 3-15 years of age. Most cases develop during the late winter months or early spring. Males and females are equally affected by the condition.

Cases of slapped cheek syndrome usually follow a cyclical pattern with an upsurge in cases occurring every 4-7 years.

Parvovirus B19 is contagious

Airborne viruses are viruses that can survive for a short period of time in the outside environment.

Parvovirus B19 is an airborne virus that is spread in much the same way as the cold or flu viruses. It can be spread through coughs and sneezes that release tiny droplets of contaminated saliva which are then breathed in by another person.

At risk groups

In children, slapped cheek syndrome is almost always a mild, self-limiting infection, which means that it will get better by itself without the need for treatment.

However, there are certain groups of people in which a parvovirus B19 infection can cause serious symptoms and complications. These are listed below.

• People with certain blood disorders, such as sickle cell anaemia, where the blood does not contain enough healthy red blood cells (anaemia) and where infection can lead to a further and more severe loss of red blood cells.
• Pregnant women without immunity - parvovirus B19 infection can increase the risk of a miscarriage because the virus can cause severe anaemia in the unborn child.
• People with a weakened immune system (immunocompromised) either due to a side effect of treatment, such as chemotherapy, or from a condition such as HIV. These groups can experience prolonged, and sometime severe, symptoms of infection.

Outlook

The outlook for children with slapped cheek syndrome is excellent. The symptoms will usually pass within 4-5 weeks, and serious complications are very rare.

The outlook for people who are in ‘at risk’ groups is generally good, as long as the condition is recognised and treated promptly.

People with blood disorders will usually require a blood transfusion to restore the full amount of red blood cells.

Pregnant women with a potential risk of having a miscarriage may require an admission to hospital so that their unborn babies can be given a blood transfusion.

Immunocompromised people (those with weakened immune systems) can usually be treated with an injection of antibodies that have been donated by a person who has immunity to infection.

See the complications section for more information about ‘at risk groups’ and recommended treatments.

Slapped cheek syndrome - children

The symptoms of slapped cheek syndrome usually begin between 13-18 days after your child develops the parvovirus B19 infection. The symptoms usually follow three distinct stages.

First stage

The first stage is usually characterised by mild flu-like symptoms such as:

• a high temperature (fever) of 38C (100.4F) - although your child’s temperature will not usually rise above 38.5C (101F),
• sore throat,
• headache,
• upset stomach,
• fatigue, and
• itchy skin.

During the first stage of symptoms, your child will be most contagious.

Second stage

Between 3-7 days after the onset of symptoms, your child will develop a bright red rash on both cheeks (the so called ‘slapped cheeks). The rash may be particularly noticeable in bright sunlight.

Third stage

The third stage of symptoms usually begins 1-4 days after the appearance of the ‘slapped cheek’ rash.

During the third stage, the rash will usually spread to your child’s chest, stomach, arms, and thighs. The rash usually has a raised, lace-like appearance, and may cause discomfort and itching.

By this time, your child should no longer be contagious and they will be able to return to nursery, or school, without the risk of passing the infection onto others.

Parvovirus B19 infection - adults

The most common symptom of a parvovirus B19 infection in adults is joint pain and stiffness usually involving:

• your hands,
• knees,
• wrists, and
• ankles.

Half of all affected adults will also experience a rash, however, the ‘slapped-cheek syndrome’ is uncommon in adults and usually only affects around 1 in 10 people.

Other symptoms, such as a fever and sore throat, are rare in adults.

In most people, the symptoms of a parvovirus B19 infection will pass within 1-3 weeks, although 1 in 5 adults will experience recurring episodes of joint pain and stiffness for several months, sometimes years.

When to seek medical advice

Slapped cheek syndrome in children and parvovirus B19 infection in adults is usually mild and the infection should clear up without treatment.

You will probably only need to contact your GP if:

• your, or your child’s, temperature rises to 39C or above, and/or
• your, or your child’s, symptoms suddenly worsen.

When to seek urgent medical advice

People who are in the risk groups listed below are advised to contact their GP as soon as possible if they think they have developed a parvovirus B19 infection. If this is not possible, you should contact your local out-of-hour service, or NHS Direct on 0845 46 47.

• Pregnant women.
• People with a condition that is known to cause chronic anaemia, such as sickle cell anaemia, thalassaemia, and hereditary spherocytosis (an uncommon genetic condition that causes red blood cells to have a much shorter life-span than normal).
• People with a weakened immune system - as a result of a condition such as HIV, or acute leukaemia, or having invasive treatments, such as chemotherapy or steroid medication. You may also have a weakened immune system if you are taking medication to suppress your immune system because you have recently receive a bone marrow transplant, or organ donation.

Most cases of slapped cheek syndrome can be diagnosed by making a visual examination of the distinctive rash.

If you are in a high-risk group - for example, if you are a pregnant woman, or you have a weakened immune system, a blood test may be recommended if you have been in close contact with someone who is known to have a parvovirus B19 infection. The blood test can be used to check your immunity status (to see if you are immune to the infection).

If testing shows that you are not immune to parvovirus B19, treatment can begin immediately in order to prevent complications.

There is no vaccination for slapped cheek syndrome and, for most people, the infection is usually a mild illness, which quickly passes without the need for treatment.

There are a number of self-care techniques that you can use to help relieve symptoms. These are explained below.

• Painkillers, such as paracetamol, or ibuprofen, can be used to relieve symptoms, such as a high temperature, headache, and joint pain. Children who are 16 years of age, or under, should not take aspirin.
• Antihistamines can be used to relieve the symptoms of itchy skin. Some antihistamines are not suitable for children who are under two years of age, so you should check with your pharmacist beforehand.
• Another way to soothe itchy skin is to use a moisturising lotion.
• Make sure that you (or your child) get plenty of rest and drink plenty of fluids as this will help to relieve the symptoms of sore throat and a high temperature.

Pregnancy

If you develop a parvovirus B19 infection during pregnancy, and you do not have immunity, there is a one in three chance that you will pass the infection onto your unborn baby.

There is then a risk that your baby will develop severe anaemia. This in turn can cause heart failure and an abnormal collection of fluid inside the tissue of your baby (hydrops fetalis).

Due to this risk, it is likely that you will be given regular ultrasound scans so that the health of your baby can be carefully assessed. If your baby does show signs of severe anaemia, they may be treated with a blood transfusion.

A parvovirus B19 infection during pregnancy carries a risk of miscarriage or still birth that is estimated to be between 3-10 per cent.

Parvovirus B19 infection does not cause birth defects.

Blood abnormalities

If you have sickle-cell anaemia, or other abnormalities of the haemoglobin (red blood cells), parvovirus B19 can cause acute, severe anaemia.  This is known as an aplastic crisis.

Symptoms of an aplastic crisis include:

• very pale skin,
• fatigue,
• headache,
• high temperature (fever) of or 38C (100F) or above,
• rapid heartbeat (tachycardia),
• dizziness, and
• fainting.  

Weakened immune system

If a person with a weakened immune system (immunocompromised) develops a parvovirus B19 infection, the virus can quickly spread through their bone marrow and interfere with the production of red blood cells. This can cause symptoms of severe anaemia, a high temperature, and a sense of feeling very unwell.

Treatment will usually require being admitted to hospital where a blood transfusion can be used to treat anaemia. Antibodies that have been donated by someone who is immune to parvovirus B19 can be used to treat the underlying infection.