Erythema infectiosum is a mildly infectious and contagious exanthema of assumed viral origin, occurring in children and young adults. Since the disease frequently presents with only the cutaneous eruption, the dermatologist may be the only physician consulted by the patient. The cutaneous expression of this disease is characteristic, beginning with a livid erythema of the cheeks and progressing to a reticulated urticarial pattern on the extremities. This cutaneous pattern permits the diagnosis of this disease even in the absence of an epidemic. Although epidemiologic studies suggest transmission of this disease as an enterovirus, viral studies on five patients failed to demonstrate any viral cause.