What are Koplik spots associated with?

Koplik spots are a distinctive clinical finding associated specifically with measles. They appear as small, white lesions with a red halo inside the mouth, usually found on the buccal mucosa opposite the molars. These spots typically develop 1-2 days before the onset of the measles rash and serve as an important diagnostic indicator for the disease. Their presence is highly suggestive of measles in individuals who present with the characteristic symptoms, which include a high fever, cough, conjunctivitis, and the eventually developing rash that typically starts at the hairline and spreads downward.

In contrast, other options correspond to different viral infections that have their own unique clinical signs and presentation. Rubella, for example, does not feature Koplik spots but instead usually presents with a distinct rash and mild fever. Roseola, primarily affecting young children, is characterized by a rapid onset of high fever followed by a rosy-pink rash, while varicella (chickenpox) is recognized by its vesicular rash and systemic symptoms but also lacks Koplik spots. Thus, the association of Koplik spots with measles serves as a key characteristic in differentiating it from other viral illnesses.