What common childhood illness is characterized by a "croupy" cough?

Laryngotracheobronchitis, commonly known as croup, is a viral infection that leads to inflammation of the larynx and trachea, which results in the hallmark "croupy" cough. This cough is often described as a barking or seal-like sound and is typically worse at night. Croup is primarily seen in young children, and the cough occurs along with other symptoms such as hoarseness and difficulty breathing due to the narrowing of the upper airway.

The presence of the characteristic cough helps differentiate croup from other respiratory conditions. While asthma can cause coughing, it typically presents with wheezing rather than a croupy cough. Bronchiolitis also involves coughing, but the cough is more associated with wheezing and difficulty breathing due to lower airway inflammation. Pneumonia may cause a cough but is often accompanied by fever and localized chest pain and does not present with the distinctive cough associated with croup. The key features of croup, especially the unique cough, are what make laryngotracheobronchitis the correct answer in this case.