Erythema infectiosum B08.30

Moderately contagious, mild viral exanthema of childhood caused by infection with parvovirus B19 (more recently primate erythroparvovirus 1).

Parvovirus B19 (single-stranded DNA virus), transmission by droplet infection, incubation period 4-14 days. Parvovirus B19 is the only parvovirus that infects humans. It was found by chance in 1975 by Yvonne Cossart and named after an investigational series (number 19 in series B). The virus replicates in erythroblasts and binds to the blood group antigen P.

The prevalence of infection is 5-10% in pre-school age and 60-70% in adults.

Occurs mainly in children under 14 years of age, mostly between the ages of 4 and 10. Seasonal accumulation from June to November.

At first cheeks, spread mainly to the extensor sides of the arms, possibly legs and buttocks. No mucous membrane infestation, palms and soles of the feet are usually free.

The incubation period is 4-14 days. Mostly mild, catarrhal precursors, intense butterfly-shaped redness and swelling of the cheeks (in 75% of sufferers: ear slap face; slapped cheek appearance), 1-4 days later typical lattice- or garland-shaped erythema figures.

Morbilliform exanthema may also be caused by parvovirus B19.

Duration of exanthema: 1-3 weeks.

Often swelling of the lymph nodes, possibly accompanying arthritides (5-10% of children. The finger, foot and knee joints are particularly affected. With symptomatic treatment, the joint symptoms subside within 2-3 weeks.

Possible are petechial monopedal exanthema(glove-sock syndrome).

Acute infection: detection of virus DNA; serologically parvovirus B 19: VP2-specific IgM (positive 14 days to about 5 months after infection) and VP1/VP2-specific IgG (detectable 21 days after infection, lifelong).

• Measles: (generally much more severe clinical picture than the erythema infectiosum; with catarrhal prodromal stage: fever up to 40 °C, rhinitis, conjunctivitis, photophobia, pharyngitis, tracheitis. Enanthema; Exantherm: Red, round or oval, first pale then dark red, possibly haemorrhagic spots first behind the ears, then on the neck and trunk, finally on the extremities. Enlargement and confluence of the spots).
• Rubella: Hardly plays a role in differential diagnosis.
• Scarlet: (Fever, headache, sore throat, vomiting. Pharyngotonsillitis. Swelling of the cervical lymph nodes. Exanthema, possibly delayed by days, typically on the flexion side - groin, thigh triangle, flexion sides of the arms). Characteristic is the perioral free zone).
• Systemic lupus erythematosus: (skin lesions are present in 80% of cases. "Butterfly erythema": morbilliform, scarlatiniform, multiform, rosacea or livedo exanthema may also develop, especially in the upper back and chest; serology and immunohistology are diagnostic).
• Erysipelas: (Highly febrile [chills: ask for more details!] and highly acute clinical picture with lymphadenopathy; mostly asymmetrically localized; leukocytosis, neutrophilia, CRP, ASL significantly increased).
• Erythema exsudativum multiforme: (important DD in the case of anularly pronounced rubella; the exanthema is much more prominent than in the erythema infectiosum; an EEM usually shows succulent cocardium structures with a possibly blistery centre).
• Erythema anulare rheumaticum (most important differential diagnosis, since morphologically very similar; important differentiation: fever attacks; chronicity; already initially massive joint infestation; serology with positive rheumatoid factor!)

In immunocompromised persons, infections with parvovirus B 19 may be complicated, usually persisting chronically with the appearance of

• recurrent exanthema and continue to work with
• chronic anaemia, reticulcytopenia, erythroblastopenia (PRCA = pure red cell aplasia)
• Myocarditis
• Percarditis
• Meningitis and
• Encephalitis.

To what extent the so-called juvenile spring eruption is associated with a parvovirus B-19 infection is still unclear.

Symptomatic, lotions.

A school or day-care centre exemption is unnecessary, because with the appearance of the exanthema there is no longer any infectiousness.

Cave! in immunocompromised patients. Danger of chronic Anemia, arthritis, thrombocytopenia.

In case of infection during pregnancy danger of infection of the foetus:

• in 1st trimester: abortion in 9% of cases
• in the 2nd trimenon: 1-2 weeks after maternal disease: Hydrops fetalis (5-10% of cases) due to aplastic anemia with consecutive death of the foetus Prenatal diagnosis possible. An elevation of alpha-fetoprotein in the mother's blood may indicate an infection of the foetus even before the hydrops fetalis is detectable by ultrasound.

If an infection is detected, weekly ultrasound examinations are necessary.

1. Frank R et al (1996) Dermatologic symptoms of parvovirus B19 infections. Dermatologist 47: 365-368
2. Cheinisse L (1905) Une cinquieme maladie eruptive: Le megal-erytheme epidemique. Semaine Med 25
3. Cossart YE, Field AM, Cant B, Widdows D (1975) Parvovirus-like particles in human sera. Lancet 1: 72-73
4. Frydenberg A, Starr M (2003) Slapped cheek disease. How it affects children and pregnant women. Aust Fam Physician 32: 589-592
5. Catta R (2002) Parvovirus B19: a review. Dermatol Clin 20: 333-342
6. Scott LA et al (2003) Viral exanthems. Dermatol Online J 9: 4
7. Sticker G (1899) The new childhood disease in the Giese area (Erythema infectiosum). Z Practitioners 8
8. Willan R (1798) On Cutaneous Diseases. vol 1 (London) J. Johnson, St Paul's Church-Yard