Koplik spots are a feature of which infection?

• A. Measles
• B. Rubella
• C. Scarlet fever
• D. Hand-foot-mouth disease

Answer: (A)

Koplik spots are a sign of measles. These are tiny bluish-white spots with a red base that appear on the inside of the cheeks (buccal mucosa) early in the illness, often before the rash develops. Their appearance is highly characteristic of measles and helps distinguish it from other infections. Rubella presents with a milder fever and a face-first rash with lymph node involvement but does not show Koplik spots. Scarlet fever has a sore throat, fever, a strawberry tongue, and a sandpaper-like rash, not Koplik spots. Hand-foot-mouth disease features oral ulcers or vesicles and a rash on the hands and feet, not Koplik spots. So, the presence of Koplik spots points to measles.