What condition is indicated by the presence of Koplik spots and a rash following a fever?

The presence of Koplik spots along with the characteristic rash that appears following a fever is indicative of rubeola, commonly known as measles. Koplik spots are small, white lesions that appear on the buccal mucosa two to three days before the measles rash develops, which is distinct and typically presents as a confluent erythematous rash starting at the hairline and spreading downward.

The timeline of symptom onset is also crucial; after a febrile prodrome of approximately 10 to 12 days post-exposure, Koplik spots are followed by the rash, which helps establish the diagnosis of measles. Measles has a well-documented progression of symptoms, making this combination of signs highly specific.

Other conditions, such as rubella (German measles), do not typically present with Koplik spots and have a different rash pattern and symptom timeline. Varicella (chickenpox) would manifest with vesicular lesions rather than the measles rash, and streptococcal pharyngitis is primarily associated with throat inflammation and does not produce Koplik spots or a measles-like rash. This specificity in findings reinforces that the correct answer represents the specific disease associated with the described symptoms.