Fifth isease is one of several possible manifestations of infection by parvovirus B19. The disease is also referred to as erythema infectiosum (meaning infectious redness) and as slapped cheek syndrome, slapcheek, slap face or slapped face. In Japan the disease is called 'apple sickness or ringo-byo' in reference to the symptom of facial redness. The name "fifth disease" derives from its historical classification as the fifth of the classical childhood skin rashes or exanthems.