Dorendorfs sign, also known as Harlequin sign, refers to a rarely observed medical phenomenon. It occurs when the face turns red on one side while paling on the other, resembling the appearance of a harlequin clown. Although synonymous with Dorendorfs sign, Harlequin sign is often more widely used to describe this occurrence. The condition typically emerges as a result of neurological disorders or autonomic dysfunction within the body. While medical literature mostly refers to it as Dorendorfs sign, some professionals may interchangeably use the term Harlequin sign. It is crucial to understand the various synonyms associated with this medical condition to ensure clear communication and accurate diagnosis.