Photo Rounds

Child with malar rash

A 2-year-old boy was brought to the family physician (FP) for a rash that had developed 2 days earlier. The boy had an erythematous malar rash on his face and a “lace-like” erythematous rash on his trunk and extremities. The child had been attending day care, but no similar cases had been reported there or at home. The child was afebrile and was still playing, but with somewhat less energy than usual.

What’s your diagnosis?


 

From The Journal of Family Practice | 2016;65(5).

The patient’s “slapped-cheek” appearance led to the diagnosis: fifth disease (erythema infectiosum). The name of the diagnosis derives from the fact that it represents the fifth of 6 common childhood viral exanthems. Transmission of the causative parvovirus B19 occurs through respiratory secretions (possibly through fomites), parenterally via vertical transmission from mother to fetus, or by transfusion of blood or blood products.

Fifth disease is very contagious via the respiratory route and occurs more frequently between late winter and early summer. Up to 60% of the population is seropositive for antiparvovirus B19 immunoglobulin G (IgG) by age 20. Thirty to 40% of pregnant women lack measurable IgG to the infecting agent and are therefore presumed to be susceptible to infection. Infection during pregnancy can, in some cases, lead to fetal death.

Fifth disease is usually a biphasic illness, starting with upper respiratory tract symptoms that may include headache, fever, sore throat, pruritus, coryza, abdominal pain, diarrhea, and/or arthralgias. These constitutional symptoms coincide with the onset of viremia and usually resolve (for about a week) before the next stage begins. The second stage is characterized by a classic erythematous malar rash with relative circumoral pallor (the “slapped-cheek” appearance in children). This is followed by a “lace-like” erythematous rash on the trunk and extremities.

Pregnant women who are exposed to or have symptoms of parvovirus infection should have serologic testing. Fortunately in this case, the mother and the day care providers were not pregnant. The parents were reassured that this would go away on its own. They were told that their son should avoid excessive heat and sunlight, which can cause the rash to flare up. Children who present with the classic skin findings of fifth disease are past the infectious state and can attend school and day care. The child in this case returned to day care the next day with a note from the FP.

Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Mayeaux EJ. Fifth disease. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013:728-731.

To learn more about the Color Atlas of Family Medicine, see: www.amazon.com/Color-Family-Medicine-Richard-Usatine/dp/0071769641/

You can now get the second edition of the Color Atlas of Family Medicine as an app by clicking on this link: usatinemedia.com

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