Identify a symptom that can differentiate asthma from other respiratory diseases.

Recurrent coughing and wheezing during the night is a hallmark symptom that can help differentiate asthma from other respiratory diseases. In asthma, these symptoms often worsen at night or early in the morning due to various factors, such as the body's natural circadian rhythms and airway reactivity that can increase when lying down. The nocturnal nature of these symptoms is distinct compared to other respiratory conditions, which may not present with such a clear pattern of exacerbation.

In contrast, other signs listed involve breathing difficulty or pain that might be more transient and linked to specific activities, such as exercise, rather than the persistent and recurrent nature often seen in asthma. Therefore, the presence of nighttime coughing and wheezing is a strong indicator of asthma specifically, reinforcing its unique pattern among respiratory diseases.