What is a classic early symptom that prompts testing for cystic fibrosis in a child?

• A. Recurrent wheeze
• B. Short stature
• C. Chronic productive cough with frequent chest infections and poor weight gain
• D. Sudden chest pain

Answer: (C)

The key idea is that cystic fibrosis causes thick, sticky mucus that leads to ongoing lung infections and also pancreatic insufficiency that impairs nutrient absorption. In a child, the combination of a chronic productive cough with frequent chest infections and poor weight gain is a classic sign that prompts testing. This pattern reflects both the respiratory and digestive system involvement that defines CF, making it more specific than a simple wheeze, short stature, or sudden chest pain.

Recurrent wheeze can occur in CF but is a common feature of asthma or viral illnesses and isn’t as specific for prompting CF testing. Short stature can occur for many reasons and isn’t a unique early clue to CF. Sudden chest pain is not a typical early presentation in children with CF and would usually lead to evaluation for other causes.