Contents
Introduction
Erythema infectiosum or Fifth disease is a common exanthematous illness of childhood caused by parvovirus B19.
Epidemiology
- Transmission: Respiratory route
- Incubation period: 4-28 days (average 16-17 days)
Aetiology
Parvovirus B19 (ssDNA virus)
The virus has tropism for cells of the erythroid lineage at the pronormoblast stage
Clinical features
Peak age: 5-15 yr
Prodrome (mild)
Child will be febrile, non-toxic with nonspecific prodrome
- Low-grade fever
- Headache
- Mild upper respiratory tract infection
Characteristic rash
- Appears as erythematous flushing on the face in a ‘slapped cheek‘ appearance
- Papular purpuric ‘gloves and socks’ syndrome (PPGSS): Distinctive viral rash characterised by painful redness and swelling of the feet and hands
- Spread: Face → Trunk and proximal extremities
- Progression: Diffuse erythematous macular rash → Central clearing → Lacy or reticulated pattern → Fades (over 1-3 weeks)

Complications
- Idiopathic thrombocytopenic purpura
- Aseptic meningitis
- Adolescents or adults: Arthralgia and arthropathy
- Patients with chronic hemolytic anaemias, chronic anaemia, pancytopenia or
marrow suppression: Transient aplastic crises - Immunocompromised individuals: Virus-associated hemophagocytic syndrome
- Pregnant women: Hydrops fetalis
- Healthy children or adults: (Rare) Myocarditis
Differential diagnosis:
The name “fifth disease” comes from its place on the standard list of rash-causing childhood diseases:
- Measles (first)
- Scarlet fever (second)
- Rubella (third)
- Dukes’ disease (fourth, but is no longer widely accepted as distinct)
- Erythema infectiosum (fifth)
- Roseola (sixth)

Management
- Symptomatic management
Summary
