This site is intended for health professionals only

At the heart of general practice since 1960

Erythema infectiosum - an evidence-based guide

This new series provides evidence-based advice for conditions not covered by official guidelines. First up, erythema infectiosum.

This new series provides evidence-based advice for conditions not covered by official guidelines. First up, erythema infectiosum.


Erythema infectiosum (fifth disease) is an exanthematous viral infection caused by the human parvovirus B19. It affects mostly children aged five to 15 and occurs as minor epidemics in the spring[ref1].


The most typical symptom is a macular or slightly elevated rash starting from the face (‘slapped cheek'). The cheek lesions are flushing red but they are not tender (see picture).

Lack of tenderness, symmetry and good general condition differentiate the disease from bacterial cellulitis[ref 1, 2, 4].

A maculopapular rash follows the cheek lesions within one to four days. The rash starts from the extensor surfaces of the upper limbs and spreads in a reticular pattern predominantly on the limbs.

The rash lasts typically three to seven days, but it can disappear and reappear over several weeks.

Some patients have fever, headache, pharyngitis and myalgia before the rash appears.

During the rash, 15-30% have fever[ref 2]. Arthralgia and arthritis are rare in children, but more common in adults.

Incubation time is six to 16 days. School-aged children are mostly affected, and several members of the same family may fall ill. In the rash phase, infectivity is low, and children can attend day care or school. Isolation does not provide any benefit, such as protecting pregnant women[ref 1].

The infection is asymptomatic in many patients[ref 3].

Diagnosis and treatment

The diagnosis is based on the clinical picture.

Serological diagnosis (IgM) is available, but usually not necessary.

The virus may be demonstrated in synovial fluid or in bone marrow using PCR technique.

The treatment is symptomatic.


Parvovirus infection during pregnancy often causes an infection in the fetus[ref 3].

Infection of the fetus may cause hepatitis and bone marrow depression, which can lead to abortion in about 10%.

The parvovirus infection is diagnosed serologically. After serological confirmation, the patient is referred to a prenatal clinic. The clinic then organises fetal monitoring in order to detect infection of the fetus and possible signs of anaemia.

The virus has not been found to cause malformations.

The virus may cause aplastic crisis in a patient with malignant haematological disease.

This synopsis is taken from EBM Guidelines, a collection of treatment and diagnosis guidelines supported by evidence summaries.

Copyright Duodecim Medical Publications Ltd.

Distributed by Wiley-Blackwell. For more information,

email: or visit EBM guidelines

In parvovirus infection (5th disease) the skin on the cheeks is unevenly red, like 'slapped'; similar erythema is often visible on the lateral aspects of the upper arms and on the trunk. Parvovirus B19-3 is considered to be the causative agent. The diseasParvovirus infection

Rate this article 

Click to rate

  • 1 star out of 5
  • 2 stars out of 5
  • 3 stars out of 5
  • 4 stars out of 5
  • 5 stars out of 5

0 out of 5 stars

Have your say