Slapped cheek syndrome

Slapped cheek syndrome is a virus that only affects humans. It is also known as erythema infectiosum or fifth disease, because it is the fifth most common disease caused by a rash in children. Slapped cheek syndrome is caused by a virus called parvovirus B19.

The symptoms of slapped cheek syndrome can vary from a minor illness, possibly with headache, mild fever and sore throat, to erythema infectiosum, which produces a typical rash that appears on the cheeks, hence its name 'slapped cheek'.

It is thought that 60% of all adults in the UK have been infected with parvovirus B19 at some point. It usually affects people when they are children, between the ages of 4-12 years old. An increase in the number of infections occurs every 3-4 years, usually in schoolchildren.

Once you have had the infection, it is likely you will be immune to the virus.

Although parvovirus B19 can affect animals (canine parvovirus and feline panleukopenia virus), slapped cheek syndrome is only known to affect humans. The virus cannot pass from human to animal or vice versa.

In 20-30% of cases of slapped cheek syndrome, there are no symptoms at all. In children, the symptoms can often go unnoticed.

The incubation period of slapped cheek syndrome is between 4-20 days. Physical symptoms are not usually present during the contagious stages of the virus. People infected with slapped cheek syndrome can pass it on without knowing during the early part of the illness but, when the rash appears, you or your child are no longer contagious to others.

The following symptoms may develop when you have slapped cheek syndrome:

• mild fever or flu-like symptoms,
• headache,
• stuffy or runny nose,
• sore throat,
• tiredness,
• in a few children there may be nausea, abdominal pain, and diarrhoea,
• adults sometimes develop aches and pains in their joints, and
• in rare cases, brain (neurological) or heart circulation (cardiovascular) problems have been reported in adults.

A distinctive blotchy red rash may begin to appear on your face, which gives the appearance of 'slapped cheeks'. In most cases, the rash is not painful. However, it may become itchy, and spread to your body and limbs, and can sometimes affect the palms of your hands and soles of your feet. The rash can take between 1-3 weeks to clear and, during this time, it may appear to fade or get worse. It may also recur some time later if you have had increased exposure to sunlight or heat.

Slapped cheek in pregnancy

Most women are immune to the parvovirus B19, but if you do catch it while you are pregnant, there is only a small chance that it will affect your baby. However, if you are infected during the first 20 weeks of pregnancy, there is a slightly increased risk of miscarriage.

If you are infected by the parvovirus B19 during weeks 9-20 of your pregnancy, there is also a 3% risk that your baby will develop foetal hydrops. This is a serious condition that can cause congestive heart failure, a severe form of oedema (swelling of body tissues caused by excessive fluid) due to severe anaemia (a lack of red blood cells that affects their ability to carry oxygen). However, in some cases of foetal hydrops, the baby recovers without developing any lasting problems.

Slapped cheek syndrome is transferred from person to person through the air, in saliva or through close contact, such as through coughing and sneezing. This means it can rapidly spread through schools or nurseries easily. Occasionally, it is transmitted through blood products, but this only happens in a small minority of cases during pregnancy.

Although the virus can affect animals (canine parvovirus and feline panleukopenia virus), parvovirus B19 is the only known human form of the virus. The virus cannot pass from human to animal or vice versa.

Because the symptoms of slapped cheek syndrome are usually obvious (or absent), and they disappear within a few weeks, tests are not commonly performed to identify the virus as the cause of feeling unwell.

However, a blood test can be carried out to detect the presence of antibodies to the virus. A blood test may be conducted if you are pregnant, or if you have an immuno-deficiency (weakened immune system) or chronic red blood cell disorders, such as sickle-cell anaemia.

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. Short-term use of paracetamol or ibuprofen can be used to relieve headaches, fevers and other flu-like symptoms.

Children under 16 years old should not take aspirin (unless under the guidance of a specialist) as it may increase the risk of Reye's syndrome, a condition that affects their brain and liver. Paracetamol can be used by all ages and is most suitable for children with minor illnesses and for reducing a high temperature. For children and teenagers, the recommended dose of paracetamol is given on the box and should always be followed. Ask your GP for advice about which medications are most suitable. Painkillers, such as paracetamol and ibuprofen, are also available in liquid form, making them ideal for young children.

Adults with joint pains and swelling may need to rest and take anti-inflammatory medications, such as ibuprofen, to relieve symptoms. Joint pain and swelling in adults usually resolve without long-term problems.

To relieve any discomfort caused by the symptoms of slapped cheek syndrome, drink plenty of fluids, particularly water, and also try to rest as much as you can.

In the majority of cases, slapped cheek syndrome does not lead to complications. However, sometimes complications may arise due to an already existing condition, such as those outlined below.

During pregnancy

See your GP if you think that you may have been infected by parvovirus B19 during your pregnancy. A blood test will be carried out to identify antibodies for slapped cheek syndrome from a current, or previous, infection.

If your blood test proves positive for parvovirus B19 in the first 20 weeks of your pregnancy, you will be monitored using ultrasound examinations. This is because the chance of miscarriage is more common in infected women with the virus. A blood transfusion, directly into your baby, may improve the chances of your baby's survival, if foetal hydrops (abnormal fluid in development of baby) is diagnosed.

However, most pregnant women infected with parvovirus B19 normally have healthy babies. Most pregnant women are not at risk from slapped cheek syndrome because they are already immune. There is no evidence to suggest that reinfection or reactivation of the virus will harm your baby, or that there is any increased risk of abnormality occurring in newborns.

If you have blood abnormalities

If you have sickle-cell anaemia, or other abnormalities of the haemoglobin (red blood cells), parvovirus B19 can cause acute, severe anaemia. You may need to be admitted to hospital to receive blood transfusions. Once the infection is controlled, the anaemia should settle down. Children may be at particular risk if they already have hereditary anaemia (a disorder that runs in the family), such as hereditary spherocytosis.

If you are immuno-deficient

People with a weakened immune system (immuno-deficiency) may also need to be admitted to hospital for treatment as they may develop chronic anaemia due to slapped cheek syndrome. Speak to your GP or specialist if you suspect you are feeling unwell due to a virus.

Arthritis

Arthritis can develop after being infected with parvovirus B19, affecting the small joints of your hands and feet, with the symptoms similar to those of rheumatoid arthritis. Arthritis is more common in adults and may persist for months, although symptoms usually disappear within a few weeks. However, if you experience arthritis as a result of slapped cheek syndrome, it is unlikely you will have permanent damage to your bones or joints.

At present there is no vaccination available to prevent slapped cheek syndrome. People who have already been infected with parvovirus B19 in the past are immune to another infection.

To prevent the spread of slapped cheek syndrome, try to make sure that everyone in your household washes their hands frequently, in order to reduce the chances of the infection spreading.