An epidemic of mumps among the students of the university during the academic year 1914-1915 gave us an unusual opportunity to watch from day to day quite a number of patients sent to the contagious hospital for treatment. Mumps is a disease which is usually seen but once by the attending physician and, very commonly, the diagnosis is made by some member of the family at the time of an epidemic. This may explain why the sign I wish to describe has not attracted general attention. The difficulties in the differential diagnosis of mumps are so slight that it would seem hardly necessary to describe a new sign or one which may have been fully recognized before, but which, as seen by us, has not found its way into the textbooks. There are, however, times when swellings on the cheeks not due to specific parotitis offer some difficulties in diagnosis.
COWIE DM. THE DUCT SIGN IN MUMPS. Am J Dis Child. 1920;20(2):75–81. doi:10.1001/archpedi.1920.01910260001001