Unusual rash accompanied by enterovirus infection and human bocavirus co-infection in a 9-week-old infant in Cologne, Germany

Introduction: The family Picornaviridae is divided into several genera, including the genus Enterovirus, which includes the species Human enterovirus A to -C and Human rhinovirus A to −C. These viruses are frequently associated with respiratory and gastrointestinal diseases. Coxsackie virus and echoviruses can induce a rash in children, such as hand-foot-and-mouth disease caused by coxsackie virus A16, while rhinoviruses are associated mainly with respiratory infections. Case presentation: We describe a clinical case of mild rhinitis in a 9-week-old female infant with HBoV and enterovirus co-infection accompanied by an unusual rash that strongly resembled granuloma annulare, having plaques with raised non-scaly erythematous borders. The child was afebrile, displayed a garland-like rash that within minutes changed its pattern and had moderately elevated expression of tryptase. No other pathogens were detected. Conclusion: It was concluded that the rash originated from the double infection with enterovirus and HBoV, as no further rash-associated pathogens were detected. The case is important as it is the first description, to the best of our knowledge, of this unusual rash seen with enterovirus/HBoV co-infection, and as this condition should be taken into account in future.