A school age patient has a chronic cough for 3 months.

What do I need to do and what diagnoses should I consider?

What are the most common diagnoses?

The top 3 diagnoses of chronic cough in school aged children to adults ("the big 3") are post nasal drip syndrome, asthma and GERD. Other diagnoses to consider are infectious (mycoplasma and post viral such as adenovirus, RSV and influenza), habit cough, smoking or passive smoking and rarer causes such as bronchiectasis, CF and TB. A post-viral cough caused by hyper-reactivity is commonly seen in adults and results in a prolonged cough with inflammation and airway reactivity which is steroid responsive.

What is the likelihood of these diagnoses?

In a study of in 102 consecutive adults with chronic cough, the most common diagnoses were post nasal drip (41%), asthma (24%), GERD (21%) and chronic bronchitis (5%). Remember that chronic bronchitis is rare in children and usually seen in patients with chronic lung diseases. Often there can be multiple problems contributing to a chronic cough such as post nasal drip or GERD exacerbating asthma. Studies have shown that 2 conditions are present 53% of the time and 3 conditions 35% of the time.

What should I ask in the cough history?

A good pneumonic is PQRST to compare and contrast distinguishing features.

• What provokes the cough such as exercise, cold air, eating, smoke exposure and viral illnesses?
• What is the quality of the cough such as croupy, honking paroxysmal?
• What symptoms are related such as nasal discharge, eczema, vomiting, weakness, hemoptysis, and stomach or chest pain?
• What is the severity of the cough?
• What is the timing of the cough such as morning, eating, awake, asleep or seasonal?

What are warning signs of a more concerning diagnosis?

Warning signs would include weight loss or poor growth or development, fever, hypoxia, hemoptysis, adenopathy or masses, clubbing, persistent crackles or symptoms associated with eating.

What is the work up of chronic cough?

The work up should be guided by the warning signs listed above. A history and physical exam including a patient diary of the cough history (PQRST) should begin the evaluation. Testing should include a CXR and pulmonary function testing. A high consideration should be the "big 3" post nasal drip syndrome, asthma and GERD. If one of these diagnoses is suspected a therapeutic trial of treatment should be considered as guided by the most likely diagnoses. For a persistent cough which does not respond to treatment of the common diagnoses, additional testing including bronchoscopy, additional radiology studies such as a CT of the sinuses or chest and/or a methacholine challenge may need to be considered.

Pulmonary function testing is available at The Children's Hospital main campus, Broomfield and Parker.

For specialized testing, please contact the Breathing Center physicians at 720-777-6181.