A physician referred a nine-year-old boy with a fever and coughing. What is the likely diagnosis based on his symptoms?

The diagnosis of measles is consistent with the symptoms of fever and coughing, particularly when considering other characteristic features, such as the appearance of Koplik's spots. Measles often presents with a high fever, cough, runny nose, and conjunctivitis, followed by a characteristic rash. Koplik's spots, which are small, white lesions found on the oral mucosa, are considered pathognomonic for measles, appearing a few days before the rash itself develops.

In this case, the combination of fever and cough strongly leans toward a viral infection like measles, especially if Koplik's spots are present, which would provide definitive visual confirmation of the diagnosis. Other conditions listed, such as vesicular lesions from chickenpox or hand, foot, and mouth disease, do not primarily include a cough as a prominent symptom in their initial presentation. Similarly, mumps typically presents with parotid gland swelling rather than the respiratory symptoms highlighted in this scenario. Hence, measles is the most fitting diagnosis based on the classic presentation of symptoms described.