Erythema infectiosum - Complications of slapped cheek syndrome

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

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 can cause heart failure and an abnormal collection of fluid inside the baby’s tissues of your baby (hydrops fetalis) which can sometimes result in a miscarriage.

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.

The risk of miscarriage is highest in the first 20 weeks of your pregnancy, at around one in 10. After 20 weeks, the risk reduces significantly, but in rare cases has been known to cause miscarriage or stillbirth. It is rare for miscarriage to occur during the first trimester.

If you believe you have come into contact with the virus during pregnancy, speak to your doctor immediately.

Blood abnormalities

If you have sickle cell anaemia, thalassaemia or other blood abnormalities, parvovirus B19 can cause severe anaemia. 

This is known as an "aplastic crisis", and symptoms include:

• very pale skin
• feeling very tired
• headache
• high temperature (fever) of 38C (100F) or above
• rapid heartbeat (tachycardia)
• dizziness
• fainting

If you experience an aplastic crisis, it is likely that you will need to be admitted to hospital and given a blood transfusion. After having a blood transfusion, most people will make a full recovery.

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.

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.