Koplik's spots, also known as Koplik's sign, are small white spots that may appear on the inner lining of the mouth and throat. They are a diagnostic feature of measles, a viral infection that is highly contagious. While Koplik's spots are most commonly associated with measles, they may also be a symptom of other diseases such as rubella, scarlet fever, and hand, foot, and mouth disease. Other synonyms for Koplik's spots include enanthem, papule, and mucosal rash. These terms are often used interchangeably and refer to the same small, white, or red spots found on the mucous membrane inside the mouth.
