Also called Fifth Disease, or Slapped Cheek Syndrome. Common childhood condition.Encyclopedia Entry for Erythema Infectiosum :Erythema infectiosum - (Slapped cheek syndrome; fifth disease) Parvovirus B19 (Parvovirus)Encyclopedia Entry for Erythema Infectiosum :Erythema infectiosum (Fifth disease). Source of disease: Parvovirus B19