Final answer:
The symptoms mentioned represent croup, a common respiratory illness in children under 3 years old, characterized by a barking cough and stridor due to inflammation of the larynx and trachea.
Step-by-step explanation:
The illness described in the question, with symptoms including variable fever, inspiratory stridor, hoarseness, and a harsh, barking, nonproductive cough in young children, is known as croup. Croup is a respiratory condition that occurs primarily in children under the age of 3 and is characterized by inflammation of the larynx and trachea. It is most often caused by a viral infection, which leads to swelling around the vocal cords resulting in the characteristic barking cough and difficulty breathing.
It is important to differentiate croup from other respiratory conditions like pertussis (whooping cough), which is caused by Bordetella pertussis and characterized by severe coughing fits followed by a 'whooping' sound. The different names for respiratory system inflammations are specified by their location and symptoms, such as rhinitis (nasal cavity inflammation), pharyngitis (sore throat), and laryngitis (inflammation of the larynx), among others. Each condition presents with distinct signs like cough, shortness of breath, wheeze, or stridor, voice changes, and pain with swallowing.