enanthem enanthem enanthem or enanthema is a rash (small spots) on the mucous membranes. it is characteristic of patients with viral infections causing hand foot and mouth disease, measles, and sometimes chicken pox, or covid-19. in addition, bacterial infections such as scarlet fever may also be a cause of enanthema. the aforementioned diseases usually present with exanthema and enanthema. enanthemrubella (german measles) enanthemaspecialtyinfectious diseases, dermatology differential diagnosissmallpox enanthema can also indicate hypersensitivity.