Which symptom is specifically associated with Kawasaki disease?

Kawasaki disease, a condition that primarily affects children, is characterized by a range of symptoms that can lead to serious cardiovascular complications if not treated promptly. One of the hallmark features of Kawasaki disease is the presence of a "strawberry tongue," which is noted for its red, swollen appearance that resembles the surface of a strawberry. This symptom arises from inflammation of the tongue’s papillae and is part of a constellation of mucocutaneous manifestations seen in the disease.

The other symptoms mentioned, such as a chronic cough, swollen lymph nodes, and rash on the legs, can be associated with various infectious or systemic conditions but are not specifically characteristic of Kawasaki disease. These symptoms do not capture the unique clinical picture that highlights Kawasaki disease, where the strawberry tongue serves as a significant diagnostic clue, often in conjunction with fever, conjunctivitis, and other systemic signs. Thus, the correct choice emphasizes a distinctive manifestation linked to Kawasaki disease rather than other more generalized symptoms.