Herpangina is a clinical syndrome whose sine qua non is the direct observation of characteristic lesions. Once seen as in epidemics of herpangina the local lesions are not likely to be confused with other clinical conditions. Zahorsky's detailed description of the hallmark lesions and Curnen's in Nelson's textbook are explicit. The latter author succinctly writes, "the characteristic discrete lesions appear initially as white or greyish vesicles, later as shallow ulcers 1 to 5 mm in diameter, each surrounded by a red areola."