Roseola infantum is a common viral infection among young children that causes a fever and rash. It is also known by various synonyms, which include sixth disease, exanthem subitum, roseola, baby measles, three-day fever, and sudden rash. The term "sixth disease" refers to the order in which it was classified among the six common viral exanthems of childhood. "Exanthem subitum" translates to "sudden rash," signifying the rapid onset of the characteristic rash following a high fever. "Baby measles" is a misnomer as it has no connection to measles, while "three-day fever" describes the duration of the main symptom. Regardless of the name used, the disease is generally mild and self-limiting, and symptoms can be managed with typical fever-reducing medications.