 The earliest known depiction of an individual with syphilis is Albrecht Dürer 's Syphilitic Man , a woodcut believed to represent a Landsknecht , a Northern European mercenary . The myth of the femme fatale or " poison women " of the 19th century is believed to be partly derived from the devastation of syphilis , with classic examples in literature including John Keats ' La Belle Dame sans Merci . 
